[torch deploy] add register_module_source (#58290)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58290
this is a helper function to get some python source code loaded
on each interpreter without having to use the standard import system
or packages. Useful for debugging or for writing wrapper classes for
handling loaded modules.
Test Plan: Imported from OSS
Reviewed By: wconstab
Differential Revision: D28435306
Pulled By: zdevito
fbshipit-source-id: b85c16346b9001cd7350d65879cb990098060813
