Add support for MI Air Conditioner Companion MCN
Hello,

Would it be possible to add support for the Mi Air Conditioner Companion MCN?

**Model:** `lumi.acpartner.mcn02`
**SKU:** `KTBL03LM`
**Link:** https://www.mi.com/buy/detail?product_id=9726

When setup in the plugin, it seems to connect successfully and is seen as a switch, but there are no additional controls. 
I see that [python-miio](https://github.com/rytilahti/python-miio) has his support, you can refer to [python-miio#809](https://github.com/rytilahti/python-miio/pull/809).
If there is anything I can provide (logs, testing, etc.), I would be happy to help the best I can.