ui: fixed some ui related bugs

* aggregation edges only connect toplevel nodes
* fixed aggregation click for undo and redo
* don't show edge name in search field, because they are not searchable
* clear search field when clicking aggregation
* leave active nodes active when clicking edges

src/lib/component/controller/UndoRedoController.cpp

@@ -33,7 +33,7 @@ void UndoRedoController::handleMessage(MessageActivateEdge* message)
 		return;
 	}
 
-	Command command(std::make_shared<MessageActivateEdge>(*message), (message->type == Edge::EDGE_AGGREGATION ? 0 : 1));
+	Command command(std::make_shared<MessageActivateEdge>(*message), (message->isAggregation() ? 0 : 1));
 	processCommand(command);
 }