MQTT: Send Setpoints

The command publishes a JSON payload to an MQTT topic sending a specific setpoint value:

mqttx pub -t 'drivr/v1/{slug}/input/sp/s/{systemUuid}/json'
          -h mqtt.drivr.cloud -l mqtts -p 8883
          --key client.key --cert certificate.pem --ca ca.pem
          -f json -m 
'{
    "characteristicUuid": "6ee642c1-45da-4d60-a88c-503062eb78a7",
    "componentUuid": "00f80405-55a3-4d8e-91c3-14a10f028cf9",
    "serviceUuid": "cb6b38a7-824f-4529-843f-acad06a67e69",
    "systemUuid": "e787f31a-7dad-460c-9b32-701513c3b2d3",
    "value": true
}'