Add reporting of C++ memory to V8's heap growing strategy via
existing EmbedderHeapTracer interface.

In addition, introduce API-level NoGarbageCollectionScope which
allows to temporarily avoid scheduling GC finalizations. Replace
internal NoGCScope with NoGarbageCollectionScope and remove
NoGCScope.

Bug: chromium:1056170
Change-Id: I0ad3dfd67eb81f09f48e2ab87f9bbece7491ed71
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2650210
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72345}