[Profiler] Expose `profilerType` in Python
Summary: It's currently possible for C++ callers to check if there is an active profiler. This adds Python API parity. For now we just use `torch._C._autograd` namespace, as this is mostly for first party frameworks like RPC. (We can always move to public API if there is demand.)
Test Plan: Added unit test
Differential Revision: D35602425
Pull Request resolved: https://github.com/pytorch/pytorch/pull/75754
Approved by: https://github.com/rohan-varma
