Differential - add unit and lint information to diff view

Summary:
see title. Note that fields that use customs storage don't work because I didn't think it made sense to load a revision object to get that data. Further, we don't have a revision id at some points, so its not clear what does / does not work...?

Also added a link to upsell this diff view as I had trouble finding it.

Test Plan: viewed some diffs

Reviewers: epriestley, vrana

Reviewed By: epriestley

CC: chad, aran, Korvin

Maniphest Tasks: T2026

Differential Revision: https://secure.phabricator.com/D3962