Slide curtains, add slide speed control into integration

Related to this integration:

Here is the new feature that is added which will be awesome to control from Home Assistant.

Scenarios would be, for morning alert open super slowly not to make any noise, and right after that set it back to 100% speed. Otherwise keeping it at 10% speed all the time would make it much unusable :slight_smile: Or setting it to 10% before the sleep is annoying etc. :slight_smile: