Deprecate `textScaleFactor` in favor of `textScaler`, in preparation for Android 14 [Non-linear font scaling to 200%](https://developer.android.com/about/versions/14/features#non-linear-font-scaling). The `TextScaler` class can be moved to `dart:ui` in the future, if we decide to use the Android platform API or AndroidX to get the scaling curve instead of hard coding the curve in the framework.

I haven't put the Flutter version in the deprecation message so the analyzer checks are failing. Will do so after I finish the migration guide.

**Why `TextScaler.textScaleFactor`**
The author of a `TextScaler` subclass should provide a fallback `textScaleFactor`. By making `TextScaler` also contain the `textScaleFactor` information it also makes it easier to migrate: if a widget overrides `MediaQueryData.textScaler` in the tree, for unmigrated widgets in the subtree it would also have to override `MediaQueryData.textScaleFactor`, and that makes it difficult to remove `MediaQueryData.textScaleFactor` in the future.

## A full list of affected APIs in this PR

Deprecated: The method/getter/setter/argument is annotated with a `@Deprecated()` annotation in this PR, and the caller should replace it with `textScaler` instead. Unless otherwise specified there will be a Flutter fix available to help with migration but it's still recommended to migrate case-by-case.
**Replaced**:  The method this `textScaleFactor` argument belongs to is rarely called directly by user code and is not overridden by any of the registered custom tests, so the argument is directly replaced by `TextScaler`.
**To Be Deprecated**:  The method/getter/setter/argument can't be deprecated in this PR because a registered customer test depends on it and a Flutter fix isn't available (or the test was run without applying flutter fixes first). This method/getter/setter/argument will be deprecated in a followup PR once the registered test is migrated.

### `Painting` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `InlineSpan.build({ double textScaleFactor = 1.0 })` argument | **Replaced** | | 
| `TextStyle.getParagraphStyle({ double TextScaleFactor = 1.0 })` argument | **Replaced** | |
| `TextStyle.getTextStyle({ double TextScaleFactor = 1.0 })`  argument| Deprecated | Can't replace: https://github.com/superlistapp/super_editor/blob/c47fd38dca4b7f43611690913b551a1773c563d7/super_editor/lib/src/infrastructure/super_textfield/desktop/desktop_textfield.dart#L1903-L1905|
| `TextPainter({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `TextPainter.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `TextPainter.computeWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |
| `TextPainter.computeMaxIntrinsicWidth({ double TextScaleFactor = 1.0 })` argument | Deprecated | |

### `Rendering` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `RenderEditable({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderEditable.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |
| `RenderParagraph({ double TextScaleFactor = 1.0 })` constructor argument | Deprecated | |
| `RenderParagraph.textScaleFactor` getter and setter | Deprecated | No Flutter Fix, not expressible yet |

### `Widgets` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `MediaQueryData({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/test/text_scale_factor_test.dart#LL39C21-L39C35 |
| `MediaQueryData.textScaleFactor` getter | Deprecated | |
| `MediaQueryData.copyWith({ double? TextScaleFactor })` argument | Deprecated | |
| `MediaQuery.maybeTextScaleFactorOf(BuildContext context)` static method | Deprecated | No Flutter Fix, not expressible yet  |
| `MediaQuery.textScaleFactorOf(BuildContext context)` static method | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/_functions_io.dart#L68-L70, No Flutter Fix, not expressible yet |
| `RichText({ double TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/builder.dart#L829-L843 |
| `RichText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away|
| `Text({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/914d120da12fba458c020210727831c31bd71041/packages/rfw/lib/src/flutter/core_widgets.dart#L647 , No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `Text.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `Text.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |
| `EditableText({ double? TextScaleFactor = 1.0 })` constructor argument | Deprecated | No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `EditableText.textScaleFactor` getter | Deprecated | |

### `Material` Library

| Affected API | State of `textScaleFactor` | Comment | 
| --- | --- | --- |
| `SelectableText({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | https://github.com/flutter/packages/blob/cd7b93532e5cb605a42735e20f1de70fc00adae7/packages/flutter_markdown/lib/src/builder.dart#L829-L843, No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `SelectableText.rich({ double? TextScaleFactor = 1.0 })` constructor argument | **To Be Deprecated** | The default constructor has an argument that can't be deprecated right away. No Flutter Fix because of https://github.com/dart-lang/sdk/issues/52664 |
| `SelectableText.textScaleFactor` getter | **To Be Deprecated** | A constructor argument can't be deprecated right away |

A lot of material widgets (`Slider`, `RangeSlider`, `TimePicker`, and different types of buttons) also change their layout based on `textScaleFactor`. These need to be handled in a case-by-case fashion and will be migrated in follow-up PRs.

`for (final InlineSpan child in children ?? const <InlineSpan>[])` bad

Fixes https://github.com/flutter/flutter/issues/126337

I'd like to find out the `fontSize` of a `PlaceholderSpan`, and currently there doesn't seem to be a way to do `TextStyle` cascading in the framework:

 `InlineSpan.visitChildren` traverses the entire `InlineSpan` tree using a preorder traversal, and nodes that don't have "content" will be skipped (https://master-api.flutter.dev/flutter/painting/InlineSpan/visitChildren.html): 

> Walks this [InlineSpan](https://master-api.flutter.dev/flutter/painting/InlineSpan-class.html) and any descendants in pre-order and calls visitor for each span that has content.

which makes it impossible to do `TextStyle` cascading in the framework: 
- `InlineSpan`s with a non-null `TextStyle` but has no content will be skipped
- `visitChildren` doesn't directly expose the hierarchy, it only gives information about the flattened tree.

This doesn't look like a breaking change, most internal customers are extending `WidgetSpan` which has a concrete implementation of the new method.

Alternatively I could create a fake `ui.ParagraphBuilder` and record the `ui.TextStyle` at the top of the stack when `addPlaceholder` is called. But `ui.TextStyle` properties are not exposed to the framework.

* improve caret caching, fix caret for empty text/line, `getLocalRectForCaret` now reports the real rect that will be painted.
move caret x-coordinate clamping to RenderEditable since TextPainter doesn't know about clipping.

* comments

* review

Use `curly_braces_in_flow_control_structures` for `foundation`, `gestures`, `painting`, `physics` (#104610)

* Use `curly_braces_in_flow_control_structures` for `foundation`

* Use `curly_braces_in_flow_control_structures` for `gestures`

* Use `curly_braces_in_flow_control_structures` for `painting`

* Use `curly_braces_in_flow_control_structures` for `physics`

* fix comments

* remove trailing space

* fix TODO style

* migrates lib/foundation and lib/widgets

* migrates lib/painting and lib/material

* migrates lib/cupertino, lib/gestures, lib/services, lib/semantics and lib/rendering

* fixes failing tests

* migrates test/

* improves hashing of lists

Update samples to use repo analysis options, Fix sample templates and a ton of analyzer issues (#77868)

Fixes https://github.com/flutter/flutter/issues/75622

Now that https://github.com/dart-lang/sdk/issues/41985 is fixed, the
analyzer detects dead code due to "unnecessary" null checks.  Since we
want to retain null checks in Flutter even when they appear
unnecessary (in order to preserve runtime behavior in weak mode), we
need to suppress these dead code hints.

Note that one assertion is removed by this PR (`heightFactor != null
|| (heightFactor == 1.0 && heightDelta == 0.0)`).  This is because
`heightFactor == 1.0 && heightDelta == 0.0` can only be true if
`heightFactor != null`, so this assertion is equivalent to simply
asserting that `heightFactor != null`, which is already asserted two
lines above.

* migrate painting to nullsafety

* address review comments

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

* Add structured errors in Animations, TabView, ChangeNotifier

* Add structured error on MaterialPageRoute, BoxBorder, DecorationImagePainter, TextSpan

* Add structured errors in Debug

* Fix test errors

* Add structured errors in Scaffold and Stepper

* Add structured errors in part of Rendering Layer

* Fix failing test due to FloatingPoint precision

* Fix failing tests due to precision error and not using final

* Fix failing test due to floating precision error with RegEx instead

* Add structured error in CustomLayout and increase test coverage

* Add structured error & its test in ListBody

* Add structured error in ProxyBox and increase test coverage

* Add structured error message in Viewport

* Fix styles and add more assertions on ErrorHint and DiagnosticProperty

* Add structured error in scheduler/binding and scheduler/ticker
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in AssetBundle and TextInput
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured errors in several widgets #1
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove unused import
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add assertions on hint messages
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix catch spacing
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in several widgets part 2 and increase code coverage
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Add structured error in flutter_test/widget_tester

* Fix floating precision accuracy by using RegExp
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove todo to add tests in Scaffold showBottomSheet
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix reviews by indenting lines and fixing the assertion orders
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Fix failing tests due to renaming class
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Try skipping the NetworkBundleTest
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

* Remove leading space in material/debug error hint
Signed-off-by: Albertus Angga Raharja <albertusangga@google.com>

This reverts commit ddd31bce.