[FEATURE REQUEST]: Sleep-Mode for "long-term"-sleeping

[HaraldGithub]

I would appreciate an optimization or change in topic "Power Control":

For MQTT/API at the moment I've [prefix]/sleep with possible payload {"sleep": x }, where "x" time in seconds.
My request is to sent "x=0" for endless sleep time (you could use this e.g. for holiday or long term switch off).

Wake up the clock again works with middle button, as at the moment.

Thank you!