Implement sending a signal when changing intent changes quality level

For now it does nothing. But I'm adding a function that should cause the combobox to pulse. That'll be a new feature so I'm implementing it in a separate commit.

Contributes to issue CURA-8849.

resources/qml/Widgets/ComboBox.qml

@@ -164,4 +164,9 @@ ComboBox
             text: delegateLabel.truncated ? delegateItem.text : ""
         }
     }
+
+    function pulse()
+    {
+        //TODO: Initiate a pulse of colour.
+    }
 }