rename old Lernkarten courseware block

lib/models/Courseware/BlockTypes/DialogCards.php

@@ -21,7 +21,7 @@ class DialogCards extends BlockType
 
     public static function getTitle(): string
     {
-        return _('Lernkarten');
+        return _('Lernkarten (Courseware)');
     }
 
     public static function getDescription(): string