[Feature Request] Enable "Entity Attribute" in widget type "Entity"

[RK62]

Up to now I ...

• set the Widget Type to Gauge
• enter the value für the Entity Attribute
• change back the Widget Type to Entity

Rendering of the attribute value works fine, so please enable the field Entity Attribute on widget type Entity

[franchiceddhu]

I'd like to be able to change the measurement unit too!