Changes to the database (#67)

In this PR are pruposed changed that come up when i started the data
migration.
Plese review them an approve and disaprove.

tests/utils/postgres/entities_test.py

@@ -1,4 +1,4 @@
 def test_import() -> None:
     from aki_prj23_transparenzregister.utils.postgres import entities
 
-    assert entities is not None
+    assert entities