Add name propagation for at::alias, add tensor.set_names (#24202)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/24202
tensor.set_names(names) is the out-of-place variant of
tensor.set_names_(names). This naming is probably confusing so I am
taking any and all suggestions.
Test Plan: - run tests [namedtensor ci]
Differential Revision: D16773014
Pulled By: zou3519
fbshipit-source-id: 61024303c1a34db631cc4cb2c53757345e40d72c
