refactor: remove SPADE dependencies

Did not look at tests yet, this is a very non-final commit.

ref: N25B-300

src/control_backend/agents/base.py

@@ -1,12 +1,11 @@
 import logging
 
-from spade.agent import Agent
+from control_backend.core.agent_system import BaseAgent as CoreBaseAgent
 
 
-class BaseAgent(Agent):
+class BaseAgent(CoreBaseAgent):
     """
     Base agent class for our agents to inherit from.
-    This ensures that all agents have a logger.
     """
 
     logger: logging.Logger