Refactoring

* splits compensation/models.py into subpackage
* renames base objects by adding suffix Mixin

compensation/models/__init__.py

@@ -0,0 +1,12 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: michel.peltriaux@sgdnord.rlp.de
+Created on: 16.11.21
+
+"""
+from .action import *
+from .state import *
+from .compensation import *
+from .eco_account import *
+from .payment import *