Introduce [de]serialize_tfw_msg() methods to abstract away enveloping

lib/tfw/networking/__init__.py

@@ -2,6 +2,7 @@
 # All Rights Reserved. See LICENSE file for details.
 
 from .serialization import decode_if_needed, encode_if_needed, serialize_all, deserialize_all
+from .serialization import serialize_tfw_msg, deserialize_tfw_msg
 from .zmq_connector_base import ZMQConnectorBase
 from .controller_connector import ControllerConnector
 from .message_sender import MessageSender

lib/tfw/networking/serialization.py

@@ -4,6 +4,14 @@
 import json
 
 
+def serialize_tfw_msg(message):
+    return serialize_all(message['key'], message)
+
+
+def deserialize_tfw_msg(*args):
+    return deserialize_all(*args)[1]
+
+
 def serialize_all(*args):
     return tuple(_serialize_single(arg) for arg in args)