Use authoritative PHIDs for Herald "Task Projects" condition
Instead, just fetch the authoritative set. This is simple, and Herald is not super performance sensitive (happens on a write) so hitting the DB once is fine.
Test Plan: Created a task with projects, verified the projects field contained the correct values when processed by Herald.
Reviewers: chad, btrahan, joshuaspence
Reviewed By: joshuaspence
Maniphest Tasks: T5707
Differential Revision: https://secure.phabricator.com/D10060