Make ApplicationTransactions preview -> submit flow less janky

Summary: ...also make it so in Pholio when you add an inline comment the preview refreshes. Fixes T2649.

Test Plan: played around in pholio leaving commentary. noted that a new inline comment would refresh the preview.

Reviewers: epriestley, chad

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T2649

Differential Revision: https://secure.phabricator.com/D6267