Remove GrCaps::SupportedRead::fSwizzle and supporting code

Add weird color types that handle the swizzling.

Change-Id: Ie37a00eb877fe5e519f7498bf749e02a2f1dc204
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/230135
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
14 files changed