Mostly tweaks for better focus management, namely:

* Use `autofocus` throughout so the a11y focus is transferred to a logical place when overlaid content pops up (screen transitions, dialogs).
* Consolidate "enabled" and "disabled" widgets into the same screen. Otherwise, when only a disabled widget is shown, there's nothing to focus on and the screen reader is lost.

This app will be use for a11y assessments. See [design doc](http://go/flutter-gar-reporting-q3-2023)    (internal only)

Updates the platform shims in dev/manual_tests so that Windows and Linux can be built. I had to update the Windows shims, because I was unable to build a Windows app there.

Also updates the analyze.dart script to report all license issues simultaneously instead of just dying after the first failure.

The only substantive code changes are in dev/bots/analyze.dart and dev/bots/test/analyze_test.dart

Change display mode of PWA default to standalone, update integration test manifest to new default

[flutter_tools][web] Add support for web app manifests and arbitrary resource files (from web/) (#48316)