21789 [macOS] Add plumbing to grab dart entrypoint args (affects: desktop, cla: yes, needs tests, platform-macos, waiting for tree to go green)

21897 Add multi-step input method support for Linux (affects: desktop, affects: text input, cla: yes, needs tests, platform-linux)

21933 Plumb through Dart entrypoint arguments on the Linux embedder (affects: desktop, cla: yes, needs tests, platform-linux)

22007 Fix FlTextInputPlugin tear down (affects: desktop, cla: yes, needs tests, platform-linux, waiting for tree to go green)

22094 Add plumbing for command line arguments on Windows (affects: desktop, cla: yes, needs tests, platform-windows, waiting for tree to go green)