refactor: use new port negotiation style

As changed in the API document, this now uses the new port negotiation style.

ref: N25B-168

src/robot_interface/state.py

@@ -2,6 +2,8 @@ import logging
 import signal
 import threading
 
+from robot_interface.utils.qi_utils import get_qi_session
+
 
 class State(object):
     """
@@ -15,6 +17,7 @@ class State(object):
         self.is_initialized = False
         self.exit_event = None
         self.sockets = []  # type: List[SocketBase]
+        self.qi_session = None  # type: None | ssl.SSLSession
 
     def initialize(self):
         if self.is_initialized:
@@ -28,6 +31,8 @@ class State(object):
         signal.signal(signal.SIGINT, handle_exit)
         signal.signal(signal.SIGTERM, handle_exit)
 
+        self.qi_session = get_qi_session()
+
         self.is_initialized = True
 
     def deinitialize(self):