[lib] Add connectionInfoValidator

Summary:
https://linear.app/comm/issue/ENG-3995/create-functions-for-migrating-the-client-stores

These validators will be used for generating converters (D8355) for schema id migration

Test Plan: Tested with later diffs if the generated converters converted the redux correctly.

Reviewers: kamil, tomek

Reviewed By: kamil

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D8381