[Kineto][Profiler] Guard event metadata python thread via verbose flag (#87096)
Summary: For Python Tracing enabled trace files, this field "python thread": 0 is repeated for every python_function event. This bloats the trace json size for large number of events or deep call stacks. Instead make this metadata guarded by the verbose flag.
Test Plan: CI
Reviewed By: robieta, slgong-fb
Differential Revision: D40325815
Pulled By: aaronenyeshi
Pull Request resolved: https://github.com/pytorch/pytorch/pull/87096
Approved by: https://github.com/slgong-fb, https://github.com/robieta
