Refactor: split network transport deserializing from message container

test/functional/p2p_invalid_messages.py

@@ -168,7 +168,7 @@ class InvalidMessagesTest(BitcoinTestFramework):
 
     def test_checksum(self):
         conn = self.nodes[0].add_p2p_connection(P2PDataStore())
-        with self.nodes[0].assert_debug_log(['ProcessMessages(badmsg, 2 bytes): CHECKSUM ERROR expected 78df0a04 was ffffffff']):
+        with self.nodes[0].assert_debug_log(['CHECKSUM ERROR (badmsg, 2 bytes), expected 78df0a04 was ffffffff']):
             msg = conn.build_message(msg_unrecognized(str_data="d"))
             cut_len = (
                 4 +  # magic