[dist_optim] add distributed functional AdamW optimizer (#50620)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/50620
Add TorchScript compatible AdamW functional optimizer to distributed optimizer
Test Plan: Imported from OSS
Reviewed By: rohan-varma
Differential Revision: D25932774
Pulled By: wanchaol
fbshipit-source-id: 64eb4aeaa3cab208d0ebbec7c4d91a9d43951947
