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/history/models/__init__.py

@@ -0,0 +1,8 @@
+from .listener import ListenerCount, MountName, Timestamp
+from .live import LiveLog
+from .played import (
+    PlayoutHistory,
+    PlayoutHistoryMetadata,
+    PlayoutHistoryTemplate,
+    PlayoutHistoryTemplateField,
+)