Add sql lite session (#71)

I added an sql lite session generator.

Changes
The function `def get_session() -> Session` 
has changed to 
`def get_session(connect_to: ConfigProvider | str) -> Session`
If a JsonFileConfig Is given the postgress conection is checked.
If a string is given that starts with `sqlite:///` an sql db is created.
The use should otherwise be the same.

tests/utils/sql/entities_test.py

@@ -0,0 +1,4 @@
+def test_import() -> None:
+    from aki_prj23_transparenzregister.utils.sql import entities
+
+    assert entities