[Reland][FSDP] Do not clean FQNs for `use_orig_params=True` (#92662)
The last PR (https://github.com/pytorch/pytorch/pull/91767/) had a land race relating to `_NamedOptimizer` + FSDP and got reverted. This is a re-land.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92662
Approved by: https://github.com/rohan-varma
