Continue reducing callsites to ArcanistDifferentialRevisionStatus in transactions

Summary: Ref T2543. Cleans up some more references to ArcanistDifferentialRevisionStatus, moving toward getting rid of it completely.

Test Plan: Planned changes, requested review, inspected the "close" one since it isn't trivial to trigger.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T2543

Differential Revision: https://secure.phabricator.com/D18408