Sync up Visual Deck Editor group by combo box to Deck Editor Dock Widget combo box. (#6291)

Took 21 minutes

Co-authored-by: Lukas Brübach <Bruebach.Lukas@bdosecurity.de>

cockatrice/src/interface/widgets/deck_editor/deck_editor_deck_dock_widget.h

@@ -41,6 +41,10 @@ public:
     {
         return nameEdit->text().simplified();
     }
+    QComboBox *getGroupByComboBox()
+    {
+        return activeGroupCriteriaComboBox;
+    }
 
 public slots:
     void cleanDeck();