added feature to tilt the cover

[chriseberlein]

add feature to set the tilt position for raffstore small changes don't work properly had to use time.sleep and a normal open/close + stop message. while adjusting the tilt you should not request a new tilt position I used a blind as device_class to get an other default symbol in HA

[grimmpp]

Thanks a lot for your contribute. Unfortunately, I'm working in parallel on something else and don't have the environment yet to test it properly. When this is available I will definitely merge it in. Would it help of you to put it in between into a separated branch?