* Splitting golden file versioning out as an argument of matchesGoldenFile

* Fixing description implementation.

* Removing unused imports

* Removing unused import

* Review feedback

Stop a text editing error from happening

Fix exception that was happening when double-double-tapping a TextField (or double long tapping).

Extra space when scrolling to selected input so that the selection caret is visible.

This reverts commit d92b3b40.

The text selection handles now feel a lot more responsive, and their implementation was cleaned up a bit.

This PR enables "Select all" on MaterialTextSelection when text is partially selected.

* Deprecates `BinaryMessages` in favor of a default instance of `BinaryMessenger`, called `defaultBinaryMessenger`
* Platform channels use the `defaultBinaryMessenger` for their binaryMessenger default argument.

Fix a bug where holding down on text selection caused the handles to flash. The fix was to only update selection when it actually changed.

This implements focus and hover handling for Material buttons. It inserts Focus widgets into the tree in order to allow buttons to be focusable via keyboard traversal (a.k.a. TAB traversal), and Listener widgets into the InkWell to allow the detection of hover states for widgets.

Addresses #11344, #1608, and #13264.

This reverts commit 18ca3754.

This fixes #32525, because it now marks the compositing bits as needing to be recalculated if the mouse tracker changes its idea of whether or not a mouse is attached.

This bug occurred because the test framework was leaking state from one test to the next (the state about whether a mouse pointer was active), and so even though there was a "passing" test when run in order with the other tests in the file, when the test was run individually (or first), it would have failed and caught the bug.

This adds an assert to make sure that after each test there are no simulated mouse pointers connected, and now calls removePointer in all of the tests where this was a problem.

This implements a DefaultFocusTraversal widget to describe the focus traversal policy for its children, defined by a FocusTraversalPolicy object from which custom policies may be created. Pre-defined policies include widget-order traversal, "reading order" traversal and directional traversal.

This reverts commit 120a1fc4.

Updated the golden file

## Description

As we've introduced offset to the Opacity layer, we have to override
`applyTransform` to make Leader/FollowerLayer work correctly.

## Related Issues

Fixes https://github.com/flutter/flutter/issues/30587

Together with https://github.com/flutter/engine/pull/8585,
this test will also exercise test against
https://github.com/flutter/flutter/issues/30586.

## Tests

I added the following tests:
* text field selection toolbar renders correctly inside opacity

This re-lands the Focus changes in #30040. Correctness changes in routes.dart, and removes the automatic requesting of focus on reparent when there is no current focus, which caused undesirable selections.

Addresses #11344, #1608, #13264, and #1678
Fixes #30084
Fixes #26704

Fix a bug where text selection handles were invisible in iOS

This reverts commit 4218c0bc.

Implements focus traversal for desktop platforms, including re-implementing the existing focus manager and focus tree.

This implements a Focus widget that can be put into a widget tree to allow input focus to be given to a particular part of a widget tree.

It incorporates with the existing FocusScope and FocusNode infrastructure, and has minimal breakage to the API, although FocusScope.reparentIfNeeded is removed, replaced by a call to FocusAttachment.reparent(), so this is a breaking change:

FocusScopeNodes must now be attached to the focus tree using FocusScopeNode.attach, which takes a context and an optional onKey callback, and returns a FocusAttachment that should be kept by the widget that hosts the FocusScopeNode. This is necessary because of the need to make sure that the focus tree reflects the widget hierarchy.

Callers that used to call FocusScope(context).reparentIfNeeded in their build method will call reparent  on a FocusAttachment instead, which they will obtain by calling FocusScopeNode.attach in their initState method. Widgets that own FocusNodes will need to call dispose on the focus node in their dispose method.

Addresses #11344, #1608, #13264, and #1678
Fixes #30084
Fixes #26704

TextField and CupertinoTextField can now specify scrollPhysics. Cupertino defaults to bouncing now.

* Disallow cursor from appearing beyond the width of the input.

* Test that verifies the cursor can't exceed the width of the input

* Use constant from editable.dart to explain 1 pixel difference in test

* Fix failing test that tested the case of overflowing spaces

* some space formattings

* always use blocks in if-else if a block is used

* format spaces in for and while

* allow multiline if conditions

* fix missing space