Support for windowShadeLevel capability

[iquix]

Hi @andrewsayre

Thank you for your great work of pysmartthings and Homeassistant ST integration.

Recently, ST decided to use Edge drivers as default. https://community.smartthings.com/t/hub-connected-devices-now-use-edge-drivers/241868

One problem might occur when using the stock Edge driver for window shades. The Edge driver no longer uses switchLevel capability, but now uses windowShadeLevel capability. https://github.com/SmartThingsCommunity/SmartThingsEdgeDrivers/blob/main/drivers/SmartThings/zigbee-window-treatment/profiles/window-treatment-profile.yml

It seems that pysmartthings and Homeassistant ST integration is not ready for this transition. I hope you could help on this problem of windowShadeLevel capability.

Thank you.