Add toggle command to mqtt topics

[psych0d0g]

as a user i have a battery powered 433mhz button near my bed to toggle the bedroom lights.. i can trigger custom mqtt messages by it using an sonoff rf_bridge. to toggle the bedroom lights from this button it would be needed for the nspanel code to be able to react to toggle commands in addition to 0 and 1 sent to the corresponding mqtt queues.