feat: indicate incomplete participant data in cards

templates/booking/create/step_2.html.twig

@@ -50,7 +50,8 @@
                                     'cardData': cardData,
                                     'index': loop.index0,
                                     'participantNumber': loop.index,
-                                    'mode': 'create'
+                                    'mode': 'create',
+                                    'isSubmitted': isSubmitted
                                 } %}
                             {% endfor %}
                         </div>