U1db implementation

Comment about style, I personally prefer:

    from zmq_transport.common.utils import (
        serialize_msg,
        deserialize_msg,
        create_get_sync_info_response_msg,
        ...
    )

But kali prefers:

    from zmq_transport.common.utils import serialize_msg
    from zmq_transport.common.utils import deserialize_msg
    from zmq_transport.common.utils import create_get_sync_info_response_msg
    ...