When Favorites is uninstalled or not visible to the viewer, hide the menu

Summary: Ref T5867. The executeOne() currently raises a policy exception if the application isn't visible to the viewer, or we fatal if the application has been uninstalled.

Test Plan:

• Viewed pages with the application uninstalled, saw working pages with no favorites menu.
• Viewed pages with the application restricted, saw working pages with no favorites menu.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T5867

Differential Revision: https://secure.phabricator.com/D17219