[Feature] Light sensor illuminance (not illuminance_lux)
**Problem description**
I bought a [mijia light sensor](https://www.zigbee2mqtt.io/devices/GZCGQ01LM.html) which I hoped to do some automations with.  
After pairing it, I found it only outputs battery sensors and illuminance.  Not illuminance_lux, this prevents it from showing up in home bridge.

**Suggested solution**
Add an illuminance support for more light sensor device options

**Are you willing to contribute to this feature?**
Yes
