Migrate from `flutter/material.dart` to `material_ui/material_ui.dart` (#10016)

* Apply dart fix "migrate_design_widgets" for decoupling migration.

This applies the migration using dart fix:

```
dart fix --apply --code=migrate_design_widgets
```

* Update pubspec.lock

* Specify material_ui and cupertino_ui package versions

* Update devtools_app_shared

* Pin package versions, update all packages

* Pin material_ui to ^1.4.0

* Add cupertino_ui to devtools_test

* Remove cupertino_ui from devtools_test

* Add DCM ignore for Flutter SDK import in Flutter apps

* Run dart fix --apply on devtools_test

* Update widget_icons package to material_ui

* Sort imports using dart fix --apply

* Specify material_ui version in example

* Add cupertino_ui to devtools_test with ignore: dependencies

* Fix SidePanel Markdown styling for dark theme and update goldens

Explicitly apply theme text styles to MarkdownStyleSheet in SidePanel
to fix dark theme contrast after migrating to package:material_ui.
Also update the memory diff goldens to match the rendered upload icon.

* Use MaterialUiCompatibilityBridge for markdown side panel

* Add description to ignore

* Increase bundle size benchmark for material_ui