Improve Zen thermostat support to enable cooling control

[SwoopX]

Improve Zen thermostat support to enable cooling control (#3382)

• Rely on attribute reporting
• Expose RConfigCoolSetpoint, RConfigMode and RConfigFanMode via API

[andynbaker]

Hey @SwoopX! I'm playing with the latest deconz image now. I was able to follow the steps to find my username and start sending commands to the api via http messages. I was able to change the mode back and forth between cooling and heating without issue. I was also able to change the fan mode back and forth between on and auto without issue.

But changing the cooling set points always resulted in an error. I set the setpoints manually on my thermostat to 74 and 75 deg F and then polled the API for the current state and got values of 2350 and 2400, respectively. When I tried to push those values back with the sensors/x/config endpoint, it returned an error each time:

This is the PUT payload: {"coolsetpoint":"2350"} This is the end point: http://[MY_HOST_IP:PORT]/api/[USERNAME]/sensors/[MY_SENSOR_ID]/config. And this is the response:
[{"error":{"address":"/sensors/2/config/coolsetpoint","description":"invalid value, 2350, for parameter coolsetpoint","type":7}}]