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

src/applications/maniphest/controller/ManiphestTaskEditController.php

@@ -665,6 +665,14 @@ final class ManiphestTaskEditController extends ManiphestController {
     }
 
     $crumbs = $this->buildApplicationCrumbs();
+
+    if ($task->getID()) {
+      $crumbs->addCrumb(
+        id(new PhabricatorCrumbView())
+          ->setName('T'.$task->getID())
+          ->setHref('/T'.$task->getID()));
+    }
+
     $crumbs->addCrumb(
       id(new PhabricatorCrumbView())
         ->setName($header_name));