Add Enum convert back to Python object support (#43121)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/43121
Test Plan: Imported from OSS
Reviewed By: SplitInfinity
Differential Revision: D23222628
Pulled By: gmagogsfm
fbshipit-source-id: 6850c56ced5b52943a47f627b2d1963cc9239408
