Show "Tnnn" crumb on Edit Task screen
Summary: Fixes T4198. We don't currently show "(Maniphest) > T123 > Edit" on the edit screen, which is inconsistent. Add the "T123" crumb.
Test Plan: {F87177}
Reviewers: chad, btrahan
Reviewed By: chad
CC: aran
Maniphest Tasks: T4198
Differential Revision: https://secure.phabricator.com/D7699