Additional changes:
- Clean up liftoff implementation of br_on_*.
- Bundle operations everywhere based on operation rather than type.
- Remove reference argument from WASM_BR_ON_* macros, to bring them in
  sync with WASM_BR_ON_CAST.
- Add missing function decoding unittests for br_on_*.

Bug: v8:7748
Change-Id: I5f5ebfac5b50b5a9a201acb435344d7471326242
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2909857Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74709}