First implementation of GrDawnProgramDataManager.

Also add GrDawnCaps to friends of GrShaderCaps, as the other backends do.

Change-Id: Iae60cae7168ad9194f7808c2f51f41de10e53071
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/230747
Commit-Queue: Stephen White <senorblanco@chromium.org>
Reviewed-by: Greg Daniel <egdaniel@google.com>
4 files changed