[Mobile] Hide Back Button

When you are at the highest level the
back button fades out and is unclickable.
When you are able to go up a level the
back button appears/fades in and is
pressable. Also removed the object type
name from the header.

platform/commonUI/browse/res/templates/back-arrow.html

@@ -22,6 +22,7 @@
 
 <!-- Back Arrow Icon used on mobile-->
 <span ng-controller="BrowseController"
-      ng-click='backArrow()'>
+      ng-click='backArrow()'
+      ng-class="checkRoot(); atRoot ? 'mobile-back-hide' : 'mobile-back-unhide'">
     <a class='type-icon icon ui-symbol'>&lt;</a>
 </span>