Temporarily support ranks + tag as pg identifier in native funcol (#120226)
As communicated in https://github.com/pytorch/pytorch/issues/93173#issuecomment-1907095208, although we are dropping `(ranks, tag)` as group identifier in funcols, there will be a grace period for migration. This PR adds temporary `(ranks, tag)` support in native funcols. It also helps us decouple the py funcol -> native funcol transition from the API change.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/120226
Approved by: https://github.com/wanchaol, https://github.com/wconstab
ghstack dependencies: #120042, #120043, #120070
