Hot water On/Off switch (combi boiler)
Hello !

First off, brilliant plug in. Thank you for all the work you've put in, seriously.

**Is your feature request related to a problem? Please describe.**
I used to have another homebridge plugin to integrate my Nest thermostat into HomeKit, and it had an on/off switch to activate the hot water heat up (and I could manually set the heating up time in the JSON settings). I have a combi boiler so I also need a way to tell my nest to heat up the hot water for some time, on top of being able to set the standard temperature functionality.

Could it be implemented in this plugin?

**Describe the solution you'd like**
Just an on/off switch in the thermostat view in homekit.

**Describe alternatives you've considered**
n/a

**Additional context**
Add any other context or screenshots about the feature request here.

Thanks !

Antoine