Revert "Metal: Add labels and debug groups to help with GPU Debugging."

This reverts commit 9e583bfa3f4573dd1894c04d5720d5165496b37e.

Reason for revert: breaking flutter, needs available checks

Original change's description:
> Metal: Add labels and debug groups to help with GPU Debugging.
>
> * Adds SK_ENABLE_MTL_DEBUG_INFO to enable labels and debug groups,
>   dependent on skia_enable_gpu_debug_layers.
>
> Bug: skia:12150
> Change-Id: I5b4538c0f6df6ceed72d7e8e6f1952fd193b7b90
> Reviewed-on: https://skia-review.googlesource.com/c/skia/+/422756
> Commit-Queue: Jim Van Verth <jvanverth@google.com>
> Reviewed-by: Greg Daniel <egdaniel@google.com>

TBR=egdaniel@google.com,jvanverth@google.com,chinmaygarde@google.com

Change-Id: I62deacb3527dc709fa8bb8c9f4631e523eae27f0
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: skia:12150
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/423816
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Greg Daniel <egdaniel@google.com>
14 files changed