feat(api): split api into multiple apps (#1626)

Fixes #1622

- split the api into 4 apps: core, history, schedule, storage
- exploded the settings into testing/prod

api/libretime_api/core/views/version.py

@@ -0,0 +1,10 @@
+from django.conf import settings
+from rest_framework.decorators import api_view, permission_classes
+from rest_framework.permissions import AllowAny
+from rest_framework.response import Response
+
+
+@api_view(["GET"])
+@permission_classes((AllowAny,))
+def version(request, *args, **kwargs):
+    return Response({"api_version": settings.API_VERSION})