[Frontend] Bug fixing

open #729
open #498
Fixed markup to use proper CSS classes
to allow tree items in Inspector Elements to
ellipsize properly, and to apply scroll regions
to the proper elements;

platform/commonUI/general/res/templates/object-inspector.html

@@ -40,7 +40,7 @@
                     <mct-representation
                             key="'edit-elements'"
                             mct-object="domainObject"
-                            class="flex-elem holder grows vscroll current-elements">
+                            class="flex-elem l-flex-col holder grows current-elements">
                     </mct-representation>
                 </div>
             </div>