[graphite] Set up atlas-based clipping.

Disabled for now as there are some correctness issues. But includes:

* Adds genID to ClipStack::SaveRecord for atlas key generation
* Adds use of ClipAtlas to find/create SW clip entries
* Fixes null analytic clip when used with atlas clip
* Various other fixes and clean up

Bug: b/388810102
Change-Id: Ia595dff40c67f3f0a7eeb1ea5df9cdaa56aeef34
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/928449
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Jim Van Verth <jvanverth@google.com>
8 files changed