Changes:
- Fix error message typo in function-body-decoder.
- Generalize wasm test macros related to reference types.
- Change wasm-gc test API to return bytes.
- Add unittests for ref.test/cast.

Bug: v8:7748
Change-Id: I361987e0b6ac90c4e89a49a8abc125757a5fc8d0
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2317319
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69220}