feat: adapt actuation receiver to state's qi_session

Makes actuation tests pass. In main, the timing of the socket no longer contains the time to receive and send data, but only the processing time of the message handler.

ref: N25B-168

src/robot_interface/endpoints/main_receiver.py

@@ -48,9 +48,6 @@ class MainReceiver(ReceiverBase):
         return {"endpoint": "negotiate/error", "data": "The requested endpoint is not implemented."}
 
     def handle_message(self, message):
-        if "endpoint" not in message:
-            return {"endpoint": "error", "data": "No endpoint provided."}
-
         if message["endpoint"] == "ping":
             return self._handle_ping(message)
         elif message["endpoint"].startswith("negotiate"):