Add timeout argument to send_command

https://gitlab.com/advian-oss/python-datastreamservicelib/-/blob/master/src/datastreamservicelib/reqrep.py?ref_type=heads#L53 https://gitlab.com/advian-oss/python-datastreamservicelib/-/blob/master/src/datastreamservicelib/reqrep.py?ref_type=heads#L47 https://gitlab.com/advian-oss/python-datastreamcorelib/-/blob/master/src/datastreamcorelib/reqrep.py?ref_type=heads#L74