#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

user/models/user_action.py

@@ -8,6 +8,7 @@ Created on: 15.11.21
 import uuid
 
 from django.db import models
+from django.utils.timezone import localtime
 from django.utils.translation import gettext_lazy as _
 
 from konova.sub_settings.django_settings import DEFAULT_DATE_TIME_FORMAT
@@ -122,3 +123,13 @@ class UserActionLogEntry(models.Model):
             comment=comment,
         )
         return action
+
+    def get_timestamp_str_formatted(self):
+        """ Getter for formatted timestamp string of the entry
+
+        Returns:
+            val (str): The formatted timestamp as string
+        """
+        val = self.timestamp
+        val = localtime(val)
+        return val.strftime(DEFAULT_DATE_TIME_FORMAT)