Move util functions to a more common place (#73519)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/73519
Move `getattr_recursive()` and `setattr_recursive()` to fx main.
Test Plan: CI
Reviewed By: khabinov
Differential Revision: D34524723
fbshipit-source-id: a656e821d9dc1d446aa80cdc03a923bf0c05aeb5
(cherry picked from commit 4835965ac72d299487be14687823ea62394f4079)
