Have GrVkTexture not derive from GrVkImage.

A side effect of this change is that I've tried to pass GrVkAttachments
around GrVkGpu instead of GrVkTextures where I could to start the
transition within the backend code.

Bug: skia:10727
Change-Id: Ibc9553cdbd7f6ae845c56aad3f25f58e4c478e46
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/379577
Reviewed-by: Jim Van Verth <jvanverth@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
14 files changed