[sparsity] Moving the sparsity python files to OSS (#56617)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56617
This migrates the sparsity to the open source
Test Plan: `buck test mode/opt //caffe2/test:ao`
Reviewed By: raghuramank100
Differential Revision: D27812207
fbshipit-source-id: cc87d9d2b486269901a4ad9b483615741a1cd712
