Move elements/ to ui/

appengine/swarming/ui/res/imp/botpage/bot-page-summary.html

 <!--
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <bot-page-summary>
 
   Usage:
 
     <bot-page-summary></bot-page-summary>
 
@@ skipping 358 matching lines @@
         }
         e.preventDefault();
         e.stopPropagation();
         this.set("_sortstr", e.detail.name + ":" + e.detail.direction);
       },
 
     });
   })();
   </script>
 </dom-module>