[c10d] update the work progress of PG periodically (#120438)
Summary:
Previously, I added lastEnqueuedSeq_ and lastCompletedSeq_ to store the states of PG progress
but log only when there is timeout detected.
We found it is not enough since the 'straggler' itself might not detect
the timeout and hence there is no log from the 'straggler'.
In this PR, we can log these states periorically so that it would be
much easier for us to identify the straggler by checking which rank
has the smallest number of lastEnqueuedSeq_
Test Plan:
Log adding, build success
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120438
Approved by: https://github.com/wconstab, https://github.com/XilunWu, https://github.com/kwen2501
