This reverts commit e763e567.

The commit broke golden tests.

Under shell/platform/windows, we have a mix of two naming schemes:
   * foo_bar_win32.h
   * win32_foo_bar.h

This renames files and identifiers to consistently use a Win32
suffix-based approach.

The handlers for the TextInput.setMarkedTextRect and
TextInput.setEditableSizeAndTransform in the win32 embedding deal in
Flutter root view co-ordinates. These need to be converted to window
co-ordinates before being passed to the TextInputManager, which deals in
Win32 window co-ordinates.

This fixes a bug wherein the IME candidates window for CJK input was
incorrectly positioned at display scales other than 100% in the OS
settings.

Fixes: https://github.com/flutter/flutter/issues/76902

* Revert "Roll Dart SDK from 632ae0dee554 to d3320177ee9a (1 revision) (#24676)"

This reverts commit 1e676eef.

* Revert "Roll Dart SDK from cf3ef9e5ced1 to 632ae0dee554 (1 revision) (#24671)"

This reverts commit 97c4d7be.

* Revert "Roll Dart SDK from ac2d5fd1c35d to cf3ef9e5ced1 (1 revision) (#24664)"

This reverts commit 7b807539.

* Revert "Roll Dart SDK from 9ef3cef4a36c to ac2d5fd1c35d (1 revision) (#24656)"

This reverts commit c574153e.

* Revert "Roll Dart SDK from 3870a33d25fb to 9ef3cef4a36c (1 revision) (#24652)"

This reverts commit 356f440a.

* Revert "Roll Dart SDK from aa0fea71185b to 3870a33d25fb (1 revision) (#24649)"

This reverts commit e30a3744.