Add a `--profile-gpu` launch argument.
When set, it generates a profile in the Trace Event Format with CPU and
GPU metrics based on GPU debug scopes.
https://profilerpedia.markhansen.co.nz/formats/trace-event-format/
The profiles are best viewed at https://ui.perfetto.dev/
Notes:
- The profiler captures everything form app start to exit.
- Being JSON based the profiles can become relatively large, but they
compress very well.
- Only OpenGL profiling is supported for now, but the report formatting
code can be shared across backends.
Pull Request: https://projects.blender.org/blender/blender/pulls/133557
f5d56a3124