Refactoring

* splits ema/models.py into subpackage
* splits konova/models.py into subpackage
* splits user/models.py into subpackage

user/models/notification.py

@@ -0,0 +1,34 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: michel.peltriaux@sgdnord.rlp.de
+Created on: 15.11.21
+
+"""
+from django.db import models
+
+from user.enums import UserNotificationEnum
+
+
+class UserNotification(models.Model):
+    """ Notifications for users
+
+    """
+    id = models.CharField(
+        max_length=500,
+        null=False,
+        blank=False,
+        choices=UserNotificationEnum.as_choices(drop_empty_choice=True),
+        primary_key=True,
+    )
+    name = models.CharField(
+        max_length=500,
+        null=False,
+        blank=False,
+        unique=True,
+        help_text="Human readable name"
+    )
+    is_active = models.BooleanField(default=True, help_text="Can be toggle to enable/disable this notification for all users")
+
+    def __str__(self):
+        return self.name