Enrich "diffusion.commit.search" with identity, status, and message information
Summary:
Depends on D19657. Ref T13197. See PHI841.
This enriches the results from `diffusion.commit.search` with information similar to the information returned by the "commits" attachment from `differential.diff.search`.
Also include unreachable, imported, message, audit status, and repository PHID.
Test Plan: Called `diffusion.commit.search` and reviewed the results, which looked sensible.
Reviewers: amckinley
Reviewed By: amckinley
Maniphest Tasks: T13197
Differential Revision: https://secure.phabricator.com/D19658