#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

ema/tables.py

@@ -115,7 +115,6 @@ class EmaTable(BaseTable, TableRenderMixin):
         )
         return html
 
-
     def render_r(self, value, record: Ema):
         """ Renders the registered column for a EMA
 
@@ -130,9 +129,7 @@ class EmaTable(BaseTable, TableRenderMixin):
         recorded = value is not None
         tooltip = _("Not recorded yet")
         if recorded:
-            value = value.timestamp
-            value = localtime(value)
-            on = value.strftime(DEFAULT_DATE_TIME_FORMAT)
+            on = value.get_timestamp_str_formatted()
             tooltip = _("Recorded on {} by {}").format(on, record.recorded.user)
         html += self.render_bookmark(
             tooltip=tooltip,