Extend mqtt-hassio.cfg for Heat Recovery Units

[pvyleta]

Heat Recovery Units (HRUs) from Brink Climate Systems are using ebusd protocol, and can be successfully integrated into home automations through ebusd. Their parameters and units are however different from the typical boilers or heat pumps, the ebusd is typically used for. This requires manual edits of mqtt-hassio.cfg even for the most basic operations, which makes the learning curve way steeper for new users.

This proposal adds the basic parameters and units typical for HRUs.

On top of it, I propose following changes/improvements:

• allow writing arbitrary values, not only curve by relaxing last line in type_switch-w-number
• join the Celsius and Kelvin messages in type_switch
• add days as a unit of time
• add device_class duration to def_global_uptime, as it seems appropriate