Mqtt monitor

[aikitori]

PR for issue https://github.com/jamesoff/simplemonitor/issues/1512

just re-tested with my mqtt server with tls.

Don't know why the linting tests fail. Feel free to give me feedback or if i should change something :)

Log:

Connected to MQTT broker.
Subscribed to topic: client/test
[mqtt_monitor_insecure] Received message: test
[mqtt_monitor_insecure] Received message: test1
2025-01-06 11:59:28    ERROR (simplemonitor) monitor failed: mqtt_monitor_insecure (Payload 'test1' did not match condition 'test'.)

logfile:

1736161229 mqtt_monitor_insecure: ok (0.000s)
1736161239 mqtt_monitor_insecure: failed since 2025-01-06 11:00:39+00:00; VFC=1 (Payload 'test1' did not match condition 'test'.) (0.000s)