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/router.py

@@ -0,0 +1,26 @@
+from rest_framework import routers
+
+from .views import (
+    CeleryTaskViewSet,
+    CountryViewSet,
+    LoginAttemptViewSet,
+    PreferenceViewSet,
+    ServiceRegisterViewSet,
+    SessionViewSet,
+    StreamSettingViewSet,
+    ThirdPartyTrackReferenceViewSet,
+    UserTokenViewSet,
+    UserViewSet,
+)
+
+router = routers.DefaultRouter()
+router.register("countries", CountryViewSet)
+router.register("login-attempts", LoginAttemptViewSet)
+router.register("preferences", PreferenceViewSet)
+router.register("service-registers", ServiceRegisterViewSet)
+router.register("sessions", SessionViewSet)
+router.register("stream-settings", StreamSettingViewSet)
+router.register("users", UserViewSet)
+router.register("user-tokens", UserTokenViewSet)
+router.register("celery-tasks", CeleryTaskViewSet)
+router.register("third-party-track-references", ThirdPartyTrackReferenceViewSet)