add return links in template

templates/group/group_view.twig

@@ -71,7 +71,6 @@
           </div>
           <div class="results" style="overflow:scroll"></div>
         </div>
-        
         <form method="post" action="/groups/{{group.id}}/users/add_multiple" id="users-add-form"></form>
       </div>
     </div>

templates/group/modify_group.twig

 {% extends 'common/layout.twig' %}
 {% block content %}
+<div class="return_link">
+    <a href="/groups/{{group.getId}}">Retour</a>
+</div>
 <div class="form_format">
 <form class="ui form {% if formstatus %} {{formstatus}} {% endif %} " action="/groups/{{group.getId}}/modify" method="post">
 <h4 class="ui dividing header">Modify the group {{group.name}}</h4>

templates/message/messenger.twig

 {% extends 'common/layout.twig' %}
 {% block content %}
-    <div class="ui right sidebar" id="list_tchat">
+    <div class="return_link">
+    <a href="/groups/{{group.getId}}">Retour</a>
     </div>
     <div class="current_tchat">
         <h2> {{group.name}}</h2>