Add inputsSize to Python IR, like outputsSize (#46779)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/46779
Test Plan: Used it in some notebooks.
Reviewed By: suo
Differential Revision: D24574005
Pulled By: dreiss
fbshipit-source-id: 78ba7a2bdb859fef5633212b73c7a3eb2cfbc380
