Add worker_name helper to dist_utils. (#34162)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34162
This avoids the "worker{}".format(..) in our unit tests to something
cleaner.
ghstack-source-id: 99713074
Test Plan: waitforbuildbot
Differential Revision: D20233533
fbshipit-source-id: 5cff952ca68af5a6d26dc5cc01463cf7756d83d9
