feat: refactoring and cleanup

templates/booking/_participant_form.html.twig

@@ -407,11 +407,8 @@
     <div id="booking-summary" hx-swap-oob="true">
         {% include 'booking/_summary.html.twig' with {
             'bookingCreateDto': bookingDto,
-            'participantCount': summaryData.participantCount,
-            'groupedSelectedRooms': summaryData.groupedSelectedRooms,
-            'assignmentCounts': summaryData.assignmentCounts,
-            'pricingData': pricingData,
-            'cmsData': cmsData
+            'summaryData': summaryData,
+            'mutableData': mutableData|default(null)
         } %}
     </div>
 {% endblock %}