* feat: add stop to openzwave (mqtt) cover
* Fix isort and black linter
* Remove supported_features for cover.
As suggested by @MartinHjelmare, not needed anymore because base class
implementation is sufficient.
https://github.com/home-assistant/core/pull/44622#discussion_r549854542
* Make a simpler version depending on idempotency
qt-openzwave already implements idempotency, see:
77e414217f/qt-openzwave/source/qtozwvalueidmodel.cpp (L180)
We can use it and trigger button release anywhen.
* Clean up
Co-authored-by: Martin Hjelmare <marhje52@gmail.com>