Revert "Flutter Driver - Create widget finders from serialized finders extensions (#67456)" (#67687)

This reverts commit 74f6fa45.

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.

This reverts commit db4dda20.

* Add punctuation for unterminated sentences in doc comments

* Addressing review nit

[Flutter Driver] Update the comments regarding the default timeout of WaitFor and WaitForAbsent commands (#58771)

* implicit-casts:false in flutter_driver

* address review comments

* Update project.pbxproj files to say Flutter rather than Chromium

Also, the templates now have an empty organization so that we don't cause people to give their apps a Flutter copyright.

* Update the copyright notice checker to require a standard notice on all files

* Update copyrights on Dart files. (This was a mechanical commit.)

* Fix weird license headers on Dart files that deviate from our conventions; relicense Shrine.

Some were already marked "The Flutter Authors", not clear why. Their
dates have been normalized. Some were missing the blank line after the
license. Some were randomly different in trivial ways for no apparent
reason (e.g. missing the trailing period).

* Clean up the copyrights in non-Dart files. (Manual edits.)

Also, make sure templates don't have copyrights.

* Fix some more ORGANIZATIONNAMEs

No code changes, just comments: I spell-checked all the comments in the repo.

* Simplified the serialization/deserialization logic of the Descendant/Ancestor matchers

* Added a composable waitForCondition Driver/extension API.

This reverts commit df2db4e5.

* Added SerializableWaitCondition for communicating between driver script on host and extension on device.

This reverts commit 8edc3f76.

This relands https://github.com/flutter/flutter/pull/35297

The followings have been done to fix the broken tests:
  1. Add `didSendFirstFrameRasterizedEvent` extension and its tests
  2. Wait for `didSendFirstFrameRasterizedEvent` instead of
     `didSendFirstFrameEvent` during start up tests
  3. Mark missed (probably newly added) start up tests as flaky

This reverts commit 68fc7231.

This should fix https://github.com/flutter/flutter/issues/31442 and https://github.com/flutter/flutter/issues/34867

* Add semantic label finders

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests