[4/n] [c10d] Introduce the multi-tenancy feature in TCPStore (#58331)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58331
This PR is the final part of a stack that addresses the GitHub issue #41614; it introduces the multi-tenancy feature to the `TCPStore` class allowing two server stores to be instantiated with the same host:port pair.
ghstack-source-id: 130676394
Test Plan:
- Run the existing and newly-introduced tests.
- Run several smoke tests including the short code snippet referred in GitHub issue #41614.
Reviewed By: H-Huang
Differential Revision: D28453850
fbshipit-source-id: f9066b164305de0f8c257e9d5736e93fd7e21ec6
