Audit - polish list view a bit

Summary:
Grab an audit we have authority over if possible, relying on how that's sorted by actor first. This gets us the best description possible of what the audit is about in the list. Also sort out highlighting; right now it looks silly on some views when everything is highlighted.

An open question in the diff - when to highlight audits?

Options I see -

• never
• don't do it on "needs attention" but other views
• calculate what percentage of shown audits user has authority over, if most ( > N% ) don't highlight, otherwise highlight
• something else
• some combo of the above

Test Plan: lists of audits looked better

Reviewers: chad, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D8876