[NCCL] Add timeout to ProcessGroup Work Wait (#40944)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/40944
This stack adds Work-level timeout for blocking wait.
This PR just changes the API to accept a default wait arg for the wait function in each ProcessGroup backend. The ProcessGroup superclass correctly waits for the given timeout by changing the CV wait to wait_for.
Closes: https://github.com/pytorch/pytorch/issues/37571
ghstack-source-id: 107835735
Test Plan: Tests in 4th PR in this stack
Reviewed By: jiayisuse
Differential Revision: D22107135
fbshipit-source-id: b38c07cb5e79e6c86c205e580336e7918ed96501
