R1:aadc1b7bf024

Add PHIDType for HeraldTransaction

Test Plan: Paste a HLXS phid to the quick-search box, get transaction page.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D15028