Sets up custom OOM handling in cppgc and installs a handler that
redirects to V8's handler when running with unified heap.

Bug: chromium:1242180
Change-Id: I68b7038a3736cc0aa92207db2c3d129a9ff68091
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3116253
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76467}