Reland "Prevent viewport.showOnScreen from scrolling the viewport if the specified Rect is already visible. (#56413)" reverted in #64091 (#64513)

Revert "Prevent viewport.showOnScreen from scrolling the viewport if the specified Rect is already visible.  (#56413)" (#64091)

This reverts commit 64d76f2f.

Prevent viewport.showOnScreen from scrolling the viewport if the specified Rect is already visible.  (#56413)

Updated references to the old button classes to the new ones in comments and documentation for tests in the material and cupertino libraries. (#62164)

This reverts commit 1e843bb6.

* Add semantics sort key for modal scope and modal barrier

* fix test

* fix test

* fix test

* fix space

* fix more tests

* addressing comments

* add language version 2.8 in packages/flutter

* enable non-nullable analyzer flag

[a11y] Make sure RenderFractionalTranslation updates its semantics after the translation field is set (#48985)

This contains the test changes for adding TargetPlatform.macOS, which was done in #43457.

The main goal of this PR is to enable tests in the material library that are currently running only on iOS to also run on macOS, but only for the tests where that makes sense. For instance, we don't run any of the haptic feedback tests on macOS.

* 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

* add missing trailing commas

* add more missing trailing commas

* add more and more missing trailing commas

This reverts commit 28b58db1.

* Re-enable const

* fix indentof statements in BlockFunctionBody

* fix indentof statements in BlockFunctionBody in tests

* add trailing commas on list/map/parameters

* add trailing commas on Invocation with nb of arg>1

* add commas for widget containing widgets

* add trailing commas if instantiation contains trailing comma

* revert bad change

* enable lint unnecessary_new

* fix tests

* fix tests

* fix tests