[PyTorch] Move NestedTensor printing to _tensor_str.py (#74000)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/74000
Now that we're in-core, we can just customize this.
ghstack-source-id: 151540966
Test Plan: Existing test_nestedtensor seems to pass
Reviewed By: ezyang
Differential Revision: D34665270
fbshipit-source-id: 5097944a4dc4fe80cea2b8576f0123466dbeab43
(cherry picked from commit d0315f46f9906c904639f43f218e439407f5b2a7)
