Roll out more FontIcons

Summary: Sidenav launcher, search typeahead results, apps launcher

Test Plan:
Used each of these items

{F275814}

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: Korvin, epriestley

Differential Revision: https://secure.phabricator.com/D11499

src/applications/diffusion/application/PhabricatorDiffusionApplication.php

@@ -19,7 +19,7 @@ final class PhabricatorDiffusionApplication extends PhabricatorApplication {
   }
 
   public function getFontIcon() {
-    return 'fa-file-code-o';
+    return 'fa-code';
   }
 
   public function isPinnedByDefault(PhabricatorUser $viewer) {