Work towards #16723

This is only safe to land after #58131 lands in google3. Only build NOTICES in asset manfiest, and load either LICENSE or NOTICES from pubspec dependencies.

Prevent WhitelistingTextInputFormatter to return a empty string if the current value does not satisfy the formatter (#57264)

* Add function to set structured error early

* Remove unused imports

* Save test handler in setUp

* Add utils file for shared test service

* Rename structured error functions

* Use setUpAll to save error handler and call initStructuredError from other init

* Rename widget inspector test service

* Remove debugging print statement

* Move error handling setting back to initServiceExtensions

* Rename structured error handler in test

* Namespace environment variable

* Rename test

Error message when size has not been set in RenderBox's performLayout should be well versed (#58151)

PR #57749 included changes to the way the project interacts with the
build process (e.g., bundling the necessary library), so should have
incremented the template version to trigger the messaging to developers.

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

Builds and bundles an 'app.so' containing AOT data, and downloads and packages the release/profile artifacts for those builds, rather than always using the debug artifacts.

Fixes https://github.com/flutter/flutter/issues/38477
Fixes https://github.com/flutter/flutter/issues/39664

BundleUtilities apparently doesn't do build-system-style timestamp
analysis when deciding what to copy, and instead just doesn't copy
things that are already present. This cleans that bundle directory on
each build, so that it includes the up-to-date library versions.

Since this is just copying from build artifacts, this is very fast; the
build steps themselves are not affected.

Fixes https://github.com/flutter/flutter/issues/58049

Fixes #58003

The .dart_tool directory can contain build assets, as well as the package_config.json file - the replacement for .packages. Remove it for the same reason we remove .packages

To make #57871 easier to land, add support for loading either LICENSES or NOTICES, preferring the later.

Update the flutter and dart scripts' locking mechanism and follow_links function to be more robust and support more platforms.

This adds support for using mkdir as a fallback if the system doesn't have flock instead of using shlock, since shlock doesn't work on shared filesystems.

It also fixes a problem in the follow_links function where it failed when the link resolved to the root directory.

This adds a new navigationMode to the MediaQueryData that indicates how focusable controls should behave under different navigation modes, currently with two modes: NavigationMode.traditional, and NavigationMode.directional.

It may seem like focusing a disabled control is not desirable, but this is useful for user interfaces that use DPAD navigation because if a control gets disabled, losing focus is disruptive to the user, and it is difficult to control where the focus will end up unless it is done explicitly.

This reverts commit f77c669d.

In #55864 a race condition was described where a done event is received before we finish connecting. This cannot happen, since async functions begin synchronously and the flag isWaitingForVm is tripped immediately, keeping onDone from exiting.

The CMake plugin build wasn't setting visibility to hidden by default,
which meant that plugins exported everything by default. This would make
bad interactions between plugins much more likely; only the intended API
should be exported by the shared library.

When you run this, bash complains that `local` is only valid in functions. Gets rid of that extraneous warning.