Rename Official support level to Featured in the frontend

This paves the way for integrating hand-picked high-quality assets
to be displayed in the project manager when accepting the
"you don't have any projects yet" dialog.

The backend name remains identical to ensure backwards compatibility
in the API.

templates/assets.phtml

@@ -116,7 +116,7 @@
                                         'official' => 'danger',
                                         'community' => 'success',
                                         'testing' => 'default',
-                                    ][$asset['support_level']]) ?>"><?php echo esc(ucfirst($asset['support_level'])) ?></span>
+                                    ][$asset['support_level']]) ?>"><?php echo esc(str_replace('Official', 'Featured', ucfirst($asset['support_level']))) ?></span>
                                 </div>
                                 <div class="asset-tags">
                                     <span class="label label-default"><?php echo esc($asset['cost']) ?></span>