Codelist integration

* adds codelist app
* adds KonovaCodeList and KonovaCode model for fetching and storing OSIRIS Codelisten entries
* adds update_codelist command for updating and fetching codes
* adds autocomplete route for using codelists in forms

codelist/urls.py

@@ -0,0 +1,14 @@
+"""
+Author: Michel Peltriaux
+Organization: Struktur- und Genehmigungsdirektion Nord, Rhineland-Palatinate, Germany
+Contact: michel.peltriaux@sgdnord.rlp.de
+Created on: 23.08.21
+
+"""
+from django.urls import path
+
+
+app_name = "codelist"
+urlpatterns = [
+
+]