Add support for CLIMA & THERMOSTAT devices

[pfiaux]

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See original thread on Planet NEEO.

Currently CLIMA devices cannot be added via the SDK.

• [ ] CLIMA type devices can be added
• [ ] THERMOSTAT type devices can be added
• [ ] Document and extend button groups with the CLIMA related widgets (thermostat UI)

[nklerk]

• [ ] Expose NEST UI

[pfiaux]

I've updated the list to be more clear, NEST UI would be part of "CLIMA related widgets". We're also aiming to make it more generic so that it's a thermostat UI that can be flexible and used by many devices not specifically tailored to a specific device.