62362 Move key event and semantics related method from WidgetTester to WidgetController (a: tests, cla: yes, framework, waiting for tree to go green)

62364 Wrap launching devtools in DevtoolsLauncher (cla: yes, tool, waiting for tree to go green)

62367 Make dartdoc warnings fatal (& cleanup of warnings) (a: accessibility, a: internationalization, a: tests, cla: yes, f: cupertino, f: material design, framework, team, waiting for tree to go green)

62368 [roll] roll to 2.10 (cla: yes, engine, team, tool)

62372 Parse .flutter-plugins-dependencies for add-to-app iOS modules, remove no-op plugin iOS folder (a: existing-apps, cla: yes, platform-ios, team, tool)

62373 Use in-memory disk for docs shards (cla: yes)