MetaMTA - make the new mail app UI a little less bad

Summary: Ref T5791. Makes the result page a little less ugly and adds the time created. Makes the detail page include more useful information about the message.

Test Plan: viewed results page and detail page and they looked better

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T5791

Differential Revision: https://secure.phabricator.com/D13410