#163 Checked icons improvement

* adds a second star icon on currently unchecked but previously checked entries
   --> can be detected easier for another check run
* simplifies some related code parts
* moves some translation string into message_templates.py
* enables session timeout after 60 minutes
* improves comment card layout sizing
* adds/updates translations

intervention/templates/intervention/detail/view.html

@@ -70,6 +70,11 @@
                                 <span>
                                     {% fa5_icon 'star' 'far' %}
                                 </span>
+                                {% if last_checked %}
+                                    <span class="rlp-gd-inv" title="{{last_checked_tooltip}}">
+                                        {% fa5_icon 'star' 'fas' %}
+                                    </span>
+                                {% endif %}
                             {% else %}
                                 <span class="check-star" title="{% trans 'Checked on '%} {{obj.checked.timestamp}} {% trans 'by' %} {{obj.checked.user}}">
                                     {% fa5_icon 'star' %}