Permit the use of "delay: n" in MQTT payloads for Arm* events

[kapstaad]

Most times we use the manual arming sequence with a 60s exit delay. At other times, such as when someone is the last to leave and forgets to arm the house, my automation notices that the house is unoccupied, and automatically arms the house.

For those occasions, I'd like the MQTT "arm_away" command to have the ability to optionally reduce or eliminate the exit delay. Perhaps the MQTT processing could be modified to permit a delay override in the payload?

For example:

{
  "command": "<my command>",
  "code": "<my pin or password>",
  "delay": "<optional override value in seconds>"
}