Add rulePHID to HeraldEffect

Summary: Ref T4195. Herald rules gained PHIDs only recently, propagate them to HeraldEffect to make some of the hook stuff eaiser.

Test Plan: iiam

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T4195

Differential Revision: https://secure.phabricator.com/D7781