chore: filled in project structure

Added some example basic files containing a functioning /message
endpoint which logs the received message to INFO.

ref: N25B-144

src/control_backend/api/v1/endpoints/message.py

@@ -0,0 +1,13 @@
+from fastapi import APIRouter, Request
+import logging
+
+from control_backend.schemas.message import Message
+
+logger = logging.getLogger(__name__)
+
+router = APIRouter()
+
+# TODO: implement
+@router.post("/message")
+async def receive_message(message: Message, request: Request):
+    logger.info("Received message: %s", message.message)