Add option to ignore failed MQTT broker connection

[joe-sydney]

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🏷️ Feature Request Type

Change to existing monitor

🔖 Feature description

A) If the MQTT monitor is used to monitor the MQTT broker and connection to the broker fails, then the monitor should be marked as down (which I believe is the current behaviour).

B) However, in cases where the MQTT is used to monitor other applications (by subscribing to messages that those applications are publishing), then loss of connectivity to the broker should not result in the monitor being down.

Currently, I am using the MQTT monitor extensively for B) in Home Assistant, and sensor states get rather messy when the Mosquitto broker is down for whatever reason.

✔️ Solution

It would be good if the monitor configuration has an additional field to optionally ignore the connectivity status. The default behaviour could still remain as is (A), but if the option this selected, then (B) applies

❓ Alternatives

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📝 Additional Context

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