Add stop button as well

[MathijsG]

Is your feature request related to a problem? Please describe. Sometimes you want to have the desk stop early, currently there is no way to do that, while a cover device does have this functionality in HomeAssistant

Describe the solution you'd like A clear and concise description of what you want to happen.

An optional stop button in between the up and down arrow. Excuse my paint skills, but this would be the idea:

The cover already has this functionality: