[graphite] Move Shareable state off key over to Resource

Change-Id: I2a52ca120a4a61e9f0f2e74698afa314dd0ece07
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/934256
Commit-Queue: Michael Ludwig <michaelludwig@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
41 files changed