Add parametrization version of weight_norm (#103001)
This done in the ordinary way, but also:
* Deprecation warning for the old API, and a migration guide
* Backwards compatibility for state_dict loading the old weight_norm
* Test for pickling and deepcopy, which was the motivating reason
weight_norm is still used by HuggingFace Wav2Vec2.
Signed-off-by: Edward Z. Yang <ezyang@meta.com>
Pull Request resolved: https://github.com/pytorch/pytorch/pull/103001
Approved by: https://github.com/albanD
