Revert "Move more Ops to skgpu::v1 namespace"

This reverts commit f3158abda33ad84e3df90cfb75a3ed82abd2fbe2.

Reason for revert: Broke Flutter build

Original change's description:
> Move more Ops to skgpu::v1 namespace
>
> GrClearOp
> GrDashOp
>
> Bug: skia:11837
> Change-Id: Ib65418952e7d4fb1e419e4942223823f22302b34
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/443518
> Reviewed-by: Michael Ludwig <michaelludwig@google.com>
> Commit-Queue: Robert Phillips <robertphillips@google.com>

TBR=robertphillips@google.com,michaelludwig@google.com,skcq-be@skia-corp.google.com.iam.gserviceaccount.com

Change-Id: Ic181ced7f5f2a8ff834fdcfb4e5265b99eef1666
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:11837
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/444365
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Robert Phillips <robertphillips@google.com>
11 files changed