Fixes#138270.
Moves the majority of the logic of MaterialStateProperties down to the widgets layer, then has the existing Material classes pull from the widgets versions.
Reverts flutter/flutter#144001
Initiated by: Piinks
Reason for reverting: Failing goldens at the tip of tree
Original PR Author: QuncCccccc
Reviewed By: {HansMuller}
This change reverts the following previous change:
Original Description:
Reverts flutter/flutter#143973
This is a reland for #138521 with an updated g3fix(cl/605555997). Local test: cl/609608958.
Part of https://github.com/flutter/flutter/issues/139243
## Description
This removes the `PlatformMenuBar.body` attribute and constructor parameter, since its deprecation period has elapsed.
## Tests
- No tests were using the deprecated attribute, so no tests were removed.
#FlutterDeprecations
Fixes https://github.com/flutter/flutter/issues/125049
This is blocking the dart roll, dart fix will now fix some invalid code that was in these test cases. These test case files are un-analyzed intentionally because they are by nature samples of broken code.