Update buildable containerPHIDs in a proper way via BuildWorker rather than via sneaky uncoordinated write

Summary:
Depends on D19065. Ref T13054. Instead of just updating containerPHID and hoping for the best, queue a proper BuildWorker to process a "your container has changed, update it" message.

We also need to remove a (superfluous) withContainerPHIDs() when loading active diffs for a revision.

Test Plan:

• Without daemons, created a revision and saw builds stick in "preparing" with no container PHID, but also stay in draft mode.
• With daemons, saw builds actually build and get the right container PHID.

Subscribers: PHID-OPKG-gm6ozazyms6q6i22gyam

Maniphest Tasks: T13054

Differential Revision: https://secure.phabricator.com/D19066