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

This reverts commit 14552a96.

[Material] Add support for customizing active + disabled state color for selection controls. (#68831)

* Add new MaterialStateProperty param to selection controls

* migrate material to nullsafety

* address review comments

* address review comments

* fix build

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

* Adds default cursor and/or mouseCursor property to a number of widgets.
* Adds `MaterialStateMouseCurrsor`.

This updates the Action API in accordance with the design doc for the changes: flutter.dev/go/actions-and-shortcuts-design-revision

Fixes #53276

* implicit-casts:false in flutter/lib/src/material

* address review comments

This adds a visualDensity attribute to checkbox, radio, icon button, and chip.

This adds actions and shortcuts arguments to WidgetsApp (and MaterialApp and CupertinoApp) to allow developers to override the default mappings on an application, and to allow for a more complex definition of the default mappings.

I've stopped using SelectAction here, in favor of using ActivateAction for all activations, but haven't removed it, to avoid a breaking change, and to allow a common base class for these types of actions. This is because some platforms use the same mapping (web) for both kinds of activations (both select and activate).

* 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

This adds a FocusableActionDetector, a widget which combines the functionality of Actions, Shortcuts, MouseRegion and a Focus widget to create a detector that defines actions and key bindings, and will notify that the focus or hover highlights should be shown or not. This widget can be used to give a control the required detection modes for focus and hover handling on desktop and web platforms.

I replaced a bunch of similar code in many of our widgets with this widget, and found that pretty much any control that wants to be focusable wants all of these features as well: focus highlights, hover highlights, and actions to activate it.

Also eliminated an extra _hasFocus variable in FocusState that wasn't being used.

This adds accessors for WidgetsBinding.instance.focusManager and WidgetsBinding.instance.focusManager.primaryFocus so that they can be more easily found in IDEs and accessed.

This adds a top level getter for WidgetsBinding.instance.focusManager.primaryFocus called primaryFocus, and a static accessor FocusManager.instance that returns WidgetsBinding.instance.focusManager.

This re-lands the change that adds focus nodes, hover, and shortcuts to switches, checkboxes, and radio buttons. (#43213), with fixes for the web tests that weren't enabled in the master that it was synced to when I first landed it.

Revert "Re-Land: Add focus nodes, hover, and shortcuts to switches, checkboxes, and radio buttons. (#43384)" (#43647)

This reverts commit 8017f63b, since it breaks web tests.

This re-lands the change that adds focus nodes, hover, and shortcuts to switches, checkboxes, and radio buttons. (#43213)

No changes from original, except for finding the right RenderBox in dev/integration_tests/android_semantics_testing/test_driver/main_test.dart.

Revert "Add focus nodes, hover, and shortcuts to switches, checkboxes, and radio buttons. (#43213)" (#43367)

This reverts commit 90006720.

In order to enable keyboard navigation to more controls, I've added focus nodes to switches, checkboxes, and radio buttons. In addition, this change enables mouse hover over these controls.

- Added tests for focus, hover, and shortcut activation for Checkbox, Radio, and Switch.

* Add checkColor to CheckboxListTile

* Create second paint for drawing check and dash

* Add activeColor test for Checkbox
Co-Authored-By: Shi-Hao Hong <shihaohong@google.com>

The new parameter defines the color of the checkbox's check mark. Default is (still) white.

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests

* lint unnecessary_new on samples

* fix tests

* Fixes resulting from audit of issues links

I looked at every link to GitHub in our repo. For cases where we had a TODO that was waiting for a bug to be fixed, and the bug has now been fixed, I applied the pending change. For cases where the link was out of date, I updated the link.

* Update run_test.dart

skip this test again since it failed on linux and macos bots