[profiler] Expose experimental performance events to python (#87905)
Reports total counts (includes time spent in all children), self counts can be calculated manully.
Differential Revision: [D40282770](https://our.internmc.facebook.com/intern/diff/D40282770/)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/87905
Approved by: https://github.com/SS-JIA
