Move SkMasks from src/codec to src/core

These are also used by some text code.

Change-Id: Ia7cffc52791a5c9a7477f2215eae9218dd75d75c
Bug: b/40045064
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/800597
Commit-Queue: Jim Van Verth <jvanverth@google.com>
Auto-Submit: Kevin Lubick <kjlubick@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>
12 files changed