add translations

I rewrote some messages to be more consistent and avoid multiplication
of messages

Resources/views/Timeline/activity_person_context.html.twig

@@ -7,7 +7,7 @@
              '%activity_type%': activity.type.name|localize_translatable_string, 
              '%date%' : activity.date|localizeddate('long', 'none') }
         ) }}</span> <span class="links"><a href="{{ path('chill_activity_activity_show', 
-        { 'person_id': person.id, 'id': activity.id} ) }}">{{ 'View the activity'|trans }}</a></span>
+        { 'person_id': person.id, 'id': activity.id} ) }}">{{ 'Show the activity'|trans }}</a></span>
         
     </div>
 </div>