Allows separating out the allocator from Heap without requiring a
heap.h include.

Drive-by:
- Rename "Retry" to "Failure".
- Avoid implicit constructors.
- Rename "RetrySpace" to "GarbageCollectionSpace" which is its only
  use.

Bug: v8:12615
Change-Id: Idac17cded8f0b2b645a2be9045ab31ffd71999b3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3456562Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79063}