* Adds `TestDisplay`
* Updates `TestPlatformDispatcher` to wrap all `Display`s and relate them to their appropriate `TestFlutterView`
* Updates `TestFlutterView` to tie `devicePixelRatio` to its display as per the documentation on `Display`

Closes #127225

Reland: Updates `flutter/test/material` to no longer use `TestWindow`

This reverts commit b2fc5f97.

Updates `flutter/test/material` to no longer use `TestWindow`

Reland (3): Removes single window assumptions from `flutter_test`

* Revert "Remove references to BindingBase.window (#122119)"

This reverts commit c7681f00.

* Revert "Remove another reference to BindingBase.window (#122341)"

This reverts commit 6ec44450.

* Revert "Reland (2): Removes single window assumptions from `flutter_test` (#122233)"

This reverts commit eb3d317e.

* Revert "Remove single view assumption from TestViewConfiguration (#122352)"

This reverts commit 927289fb.

* Revert "Updates `flutter/test/cupertino` to no longer use `TestWindow` (#122325)"

This reverts commit 67e17e45.

* Revert "Updates `flutter/test/gestures` to no longer reference `TestWindow` (#122327)"

This reverts commit c2a5111c.

* Revert "Updates `flutter/test/rendering` to no longer use `TestWindow` (#122347)"

This reverts commit 28b65e08.

* Revert "Updates `flutter_localizations/test` to stop using `TestWindow` (#122321)"

This reverts commit 01367d52.

Reland (2): Removes single window assumptions from `flutter_test`

Revert "Reland: Removes single window assumptions from `flutter_test`"

Reland: Removes single window assumptions from `flutter_test`

This reverts commit f2dd19d5.

Removes single window assumptions from `flutter_test`