FlutterDriver: deprecate enableAccessibility; redirect it to setSemantics; add setSemantics tests (#82939)

* deprecate enableAccessibility; redirect it to setSemantics
Co-authored-by: David Iglesias <ditman@gmail.com>

This reverts commit 9fd5242e.

* Revert "Revert "NNBD integration_test (#74922)" (#75030)"

This reverts commit 87b04365.

* fix bad merge issues

This reverts commit cca9592f.

Remove references to `Window`, and switch usages to `PlatformDispatcher` or `SingletonFlutterWindow` (#69617)

* Remove references to dart:ui.Window, and point usages to PlatformDispatcher or SingletonFlutterWindow, as appropriate

* remove new test platform dispatchers

* Amend documentation

* One more reland of "Driver vm service (#68654)" (#69074)" (#69077)" (#69089)"

This reverts commit e5814756.

* pub run test

This reverts commit 05ab0eba.

This reverts commit 19ce7a86.

This reverts commit 3ecac303.
Co-authored-by: Dan Field <dfield@gmail.com>

Migrate flutter_driver to use package:vm_service

This reverts commit d4112424.

Reland: #67155

Fixes analysis error caused by landing of material migration, and g3 error caused by moving of fuchsia lib.

This reverts commit e826442e.

Ensures all of the libraries that the application side code import are migrated to null safety. full null safety migration is blocked by json rpc 2 and a breaking change to vm service client.

Allow Developers to enable Accessibility testing on WebFlutterDriver and get the underlying webDriver (#65051)

* Add punctuation for unterminated sentences in doc comments

* Addressing review nit

This reverts commit cc1c9649.