Make the DelegateType class a QObject

We're not instantiating it, so it doesn't really cause a significant overhead. This silences a warning about invalid type names

src/enums/delegatetype.h

@@ -10,9 +10,9 @@
  *
  * This class is designed to define the DelegateType enumeration.
  */
-class DelegateType
+class DelegateType : public QObject
 {
-    Q_GADGET
+    Q_OBJECT
 
 public:
     /**