feat: proper determination of agency initiated bookings

For booking that are agency initiated (groups) different rules apply
concerning mutability and requirement of personal data and whether the
first participant is the applicant or not. This commit adds logic to
evaluate the agency id assigned to the booking data to decide.

templates/booking/create/step_2.html.twig

@@ -32,7 +32,7 @@
                     </div>
                     <div class="flex-1 overflow-y-auto px-4 lg:px-8 py-8">
                         <h2 class="pb-4">
-                            Teilnehmer
+                            Teilnehmer:innen
                         </h2>
 
                         {# Display form-level validation errors #}

templates/booking/create/step_4.html.twig

@@ -191,7 +191,7 @@
                             <div class="p-2 bg-primary-bg uppercase font-semibold flex justify-between items-center">
                                 <span>
                                     {{ participant.firstName }} {{ participant.lastName }}
-                                    {% if loop.first %}<span class="text-sm font-normal">(Anmelder)</span>{% endif %}
+                                    {% if loop.first and not bookingCreateDto.isInternalAgencyBooking() %}<span class="text-sm font-normal">(Anmelder:in)</span>{% endif %}
                                 </span>
                                 {% if participantPrices is defined and participantPrices[loop.index0] is defined %}
                                     <span>{{ participantPrices[loop.index0]|format_currency('EUR') }}</span>