Refactoring

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

user/models/__init__.py

@@ -0,0 +1,10 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: michel.peltriaux@sgdnord.rlp.de
+Created on: 15.11.21
+
+"""
+from .user_action import *
+from .konova_user import *
+from .notification import *