show team backups in team shift lists

shiftregister/team/templates/partials/shift_box.html

@@ -7,6 +7,9 @@
         <strong>Beginn:</strong> {{ shift.start_at }}<br>
         <strong>Dauer:</strong> {{ shift.duration }}<br>
         <strong>Belegung:</strong> {{ shift.shiftregistration_set.count }}/{{ shift.required_helpers|default:shift.room.required_helpers }}
+        {% if shift.teambackup_set.all.count %}<br>
+        <strong>Backup Teammitglied(er): {%for member in shift.teambackup_set.all%}{{member.name}}, {%endfor%}</strong>
+        {% endif %}
     </div>
     <div class="is-flex is-justify-content-end">
         <a class="button is-info is-small" href="{% url 'team:shift' shift.id %}">Details</a>

shiftregister/team/templates/shift_detail.html

@@ -7,6 +7,9 @@
 <div class="content">
     <em>{{ shift.description|linebreaksbr }}</em>
 </div>
+{% endif %}
+        {% if shift.teambackup_set.all.count %}<br>
+        <strong>Backup Teammitglied(er): {%for member in shift.teambackup_set.all%}{{member.name}}, {%endfor%}</strong>
         {% endif %}
 {% if shift.shiftregistration_set.all %}
 <h5 class="subtitle">Helfer*innen</h5>