Summary:
Adding InfoClassSchema implementation. This class contains all the
information regarding the tables that will be created and the elements within
the table that will be subscribed too.

Test Plan: Added unit tests

Reviewers: #engineering, zasgar, oazizi

Reviewed By: #engineering, zasgar, oazizi

Differential Revision: https://phab.corp.pixielabs.ai/D247

GitOrigin-RevId: 9ece889b8be9bc5ba039c3f1693926c44d0aa12c