add a timeline in view pages for viewing task transitions

Resources/views/SingleTask/show.html.twig

@@ -81,6 +81,11 @@
         {% endif %}
     </dl>
 
+    {% if timeline is not null %}
+        <h3>{{"Timeline"|trans}}</h3>
+        {{ timeline|raw }}
+    {% endif %}
+
     <ul class="record_actions">
         <li class="cancel">
             <a class="sc-button bt-cancel" href="{{ path('chill_task_singletask_list', { 'person_id': person.id } ) }}">
@@ -114,5 +119,4 @@
 
     </ul>
 
-
 {% endblock %}