expose parse_schema and __eq__ function to python and add round trip tests (#23208)
Summary:
expose necessary functions to python, and add round-way tests for
function schema str() and parsing functions.
We iterate over all the registered function schemas and get the string,
then parse the string. We compare the schema generated from parsing with
the original one, and make sure they are equal.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/23208
ghstack-source-id: 89638026
Test Plan: buck test //caffe2/test:function_schema
Reviewed By: zrphercule
Differential Revision: D16435471
fbshipit-source-id: 6961ab096335eb88a96b132575996c24090fd4c0
