[Fronted] Minor final sanding and polishing

WTD-839
.t-view-switcher > .view-switcher;
Added CSS transition to hide/show of view-switcher;
Moved .view-switcher hide/show to _frame.scss;
Tweaked .frame:hover to raise z-index to show complete border;

platform/commonUI/browse/res/templates/browse-object.html

@@ -26,7 +26,7 @@
             </mct-representation>
         </div>
 
-        <div class="view-controls sort-controls btn-bar right abs">
+        <div class="btn-bar right abs">
             <mct-representation key="'action-group'"
                                 mct-object="domainObject"
                                 parameters="{ category: 'view-control' }">