feat: implement pausing functionality in CB

ref: N25B-350

src/control_backend/agents/communication/ri_communication_agent.py

@@ -1,14 +1,14 @@
 import asyncio
 import json
 
-from pydantic import ValidationError
 import zmq
 import zmq.asyncio as azmq
+from pydantic import ValidationError
 from zmq.asyncio import Context
 
 from control_backend.agents import BaseAgent
-from control_backend.core.agent_system import InternalMessage
 from control_backend.agents.actuation.robot_gesture_agent import RobotGestureAgent
+from control_backend.core.agent_system import InternalMessage
 from control_backend.core.config import settings
 from control_backend.schemas.ri_message import PauseCommand