Add `lazy_clone_storage` to create COW storages (#110192)
This PR relands #110022 but accounts for the changes in #110191. Also, the function for creating COW storages is called `lazy_clone_storage` in this PR, instead of `try_ensure`
NOTE: COW storages do not actually copy on write yet, they just have the COW deleter and deleter context applied to them
Part of #109833
Pull Request resolved: https://github.com/pytorch/pytorch/pull/110192
Approved by: https://github.com/ezyang
