Implemented Mentionable interface in Pholio

Summary: closes T8486

Test Plan: Create a pholio mock. In an already existing object mention the pholio mock. Verify that the reference to the object exists in the pholio mock's timeline.

Reviewers: lpriestley, #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Maniphest Tasks: T8486

Differential Revision: https://secure.phabricator.com/D13402

src/__phutil_library_map__.php

@@ -6726,6 +6726,7 @@ phutil_register_library_map(array(
       'PhabricatorProjectInterface',
       'PhabricatorDestructibleInterface',
       'PhabricatorSpacesInterface',
+      'PhabricatorMentionableInterface',
     ),
     'PholioMockCommentController' => 'PholioController',
     'PholioMockEditController' => 'PholioController',

src/applications/pholio/storage/PholioMock.php

@@ -10,7 +10,8 @@ final class PholioMock extends PholioDAO
     PhabricatorApplicationTransactionInterface,
     PhabricatorProjectInterface,
     PhabricatorDestructibleInterface,
-    PhabricatorSpacesInterface {
+    PhabricatorSpacesInterface,
+    PhabricatorMentionableInterface {
 
   const MARKUP_FIELD_DESCRIPTION  = 'markup:description';