Previously the implementation of the scope iterator objects and the
debug proxy lived in src/wasm, and they are now being moved to
src/debug, to better align with the JavaScript debugging interface,
which also lives in src/debug.

Bug: chromium:1162229, chromium:1071432
Change-Id: I7f89ced88a1231ad6a923be6e85a93f1876a2024
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2621084Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72007}