Rename GrGLSLFragmentProcessor to GrFragmentProcessor::ProgramImpl

Bug: skia:11358

Change-Id: Ic179ddd9d52dca3fc0bd85b61db49097390b7f58
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/437681
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
57 files changed