Fix and improve plan view

Add link to room detail view in slot table
Fix location based nesting in plan

AKPlan/templates/AKPlan/encode_rooms.html

@@ -3,7 +3,7 @@
         {
             'id': '{{ room.title }}',
             'title': '{{ room.title }}',
-            'parentId': '{{ room.building }}',
+            'parentId': '{{ room.location }}',
         },
     {% endfor %}
     {% for building in buildings %}

AKPlan/templates/AKPlan/slots_table.html

@@ -6,7 +6,9 @@
     <tr>
         <td><b><a href="{% url 'submit:ak_detail' event_slug=event.slug pk=akslot.ak.pk %}">{{ akslot.ak.name }}</a></b></td>
         <td>{{ akslot.start | time:"H:i" }} - {{ akslot.end | time:"H:i" }}</td>
-        <td>{{ akslot.room }}</td>
+        <td>{% if akslot.room and akslot.room.pk != '' %}
+            <a href="{% url 'plan:plan_room' event_slug=event.slug pk=akslot.room.pk %}">{{ akslot.room }}</a>
+        {% endif %}</td>
     </tr>
     {% empty %}
         {% trans "No AKs" %}