Default group required

* adds access checks depending on the current group confgiguration of a user
* removes buttons for adding/editing or removing data if default group is not set for a user
* removes buttons for adding/removing related data in unshared interventions
* removes shared-user setting from share menu of an intervention if user is not zb or ets
* renames has_access() from intervention Model into is_shared_with() for more clarity
* fixes bug in group check in_group() from utils.py

intervention/templates/intervention/detail/includes/documents.html

@@ -10,10 +10,12 @@
             </div>
             <div class="col-sm-6">
                 <div class="d-flex justify-content-end">
+                    {% if is_default_member and has_access  %}
                     <button class="btn btn-outline-default btn-modal" data-form-url="{% url 'intervention:new-doc' intervention.id %}" title="{% trans 'Add new document' %}">
                         {% fa5_icon 'plus' %}
                         {% fa5_icon 'file' %}
                     </button>
+                    {% endif %}
                 </div>
             </div>
         </div>
@@ -43,9 +45,11 @@
                 </td>
                 <td class="align-middle">{{ doc.comment }}</td>
                 <td>
+                    {% if is_default_member and has_access  %}
                     <button data-form-url="{% url 'doc-remove' doc.id %}" class="btn btn-default btn-modal" title="{% trans 'Remove document' %}">
                         {% fa5_icon 'trash' %}
                     </button>
+                    {% endif %}
                 </td>
             </tr>
             {% endfor %}