Allow callers to query information about repository URIs from diffusion.repository.search
Summary: Ref T10748. Adds a "uris" attachment with URI information.
Test Plan: Queried URI information via Conduit, saw reasonable looking information.
Reviewers: chad
Reviewed By: chad
Maniphest Tasks: T10748
Differential Revision: https://secure.phabricator.com/D15822