[profiler] Add cuda synchronization points (#56651)
Summary:
Adding cuda synchronization when entering and exiting the profiler
context manager
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56651
Test Plan: CI
Reviewed By: gdankel
Differential Revision: D27926270
Pulled By: ilia-cher
fbshipit-source-id: 5cf30128590c1c71a865f877578975c4a6e2cb48
