[functorch][nn] Refactor NN stateless APIs by swapping module tensors (#92536)
- Fixes #92295
- Resolves #86708
- Resolves #92153
- Closes #92401
- Closes #92218
- Requires #91579
Refactor NN stateless APIs by swapping module tensors.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/92536
Approved by: https://github.com/jbschlosser
