widgets: add spacer, divider, tweak interface

Common/Ref.qml

@@ -1,9 +1,9 @@
-import Quickshell
 import QtQuick
+import Quickshell
 
 QtObject {
     required property Singleton service
 
     Component.onCompleted: service.refCount++
     Component.onDestruction: service.refCount--
-}
+}