R1:653bc0fa019f

Read lock all transaction edits

Summary: Ref T13054. Fixes T12714. Applies read locks to all transactions instead of only a very select subset (chat messages in Conpherence).

Test Plan: See <T13054#235650> for discussion and testing.

Maniphest Tasks: T13054, T12714

Differential Revision: https://secure.phabricator.com/D19059