Add ability for a mobile::Module to save as flatbuffer (#67351)
Summary:
Included functions:
* save_mobile_module -> saves a mobile::Module to flatbuffer
* load_mobile_module_from_file -> loads a flatbuffer into mobile::Module
* parse_mobile_module -> parses from bytes or deserialized flatbuffer
Module object
Fixes #{issue number}
Pull Request resolved: https://github.com/pytorch/pytorch/pull/67351
Reviewed By: iseeyuan
Differential Revision: D32010095
Pulled By: qihqi
fbshipit-source-id: d763b0557780f7c2661b6485105b045e41a5e8f1
