[NNC] Added some APIs for dealing directly with Bufs (instead of Tensors) (#53011)
Summary:
(also includes some python binding stuff :P)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/53011
Reviewed By: gchanan, robieta
Differential Revision: D26801120
Pulled By: Chillee
fbshipit-source-id: 42a1efb6cbc9ddc0b72b780f3d6b712b3ae62b09
