In 1.12 and before, I could get the sate of a lever with testforblock, but in 1.13, it seems like minecraft thinks that levers are not block entities and/or don't have states.
Specifically:
/data get block <x> <y> <z> lever.powered
reports "The target block is not a block entity", and
/execute if block <x> <y> <z> lever

always returns false

Do I have something wrong with my commands?