This CL refactors most of the cctests and unittests (22 out of 31) that
directly invoke heap GC, so that the corresponding internal heap methods
are called from a few specific places in boilerplate code. This will
facilitate impending changes to the interface of GC-related internal
heap methods.

Bug: v8:13257
Change-Id: Ia6773a7952501b0792b279b799171519620497d9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3869264Reviewed-by: Omer Katz <omerkatz@chromium.org>
Commit-Queue: Nikolaos Papaspyrou <nikolaos@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82927}