Move GrAtlasTextOp to skgpu::v1 namespace

Bug: skia:11837
Change-Id: I3dde13940e57763d5a8224cb1a4b555e904351d7
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/442716
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
8 files changed