Add "error" attribute for failed set commands

[arcanefoam]

Is your feature request related to a problem? Please describe

When I send a set command and the device does not respond (usually a timeout) I have no way to know that the command failed.

Describe the solution you'd like

An attribute in the device (e.g. setResult) or a mqtt topic in which I can check that the set command completed.

Additional context

This is in particular for the Wiser TRVs (which are temperamental buggers that don't always answer to commands) but could be of used to other devices.

[Morphy99]

There is no way apart from in the logs and in the Z2M front end the error will flash up. You could set a sensor up in HA (if that's what you're using) to create a notification for related mqtt error messages.

As I mentioned here perhaps Z2M should set the device as unavailable if the timeout occurs.

[github-actions]

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