Update device before calling the rendering control event callback

[davidanthoff]

This has two changes:

• It updates the device data before it calls the event callback. I think that makes a lot more sense, as client implementations then don't have to deal with the messy details of how to update the device data.
• It also utilizes the existing _handle_rendering_control_event function to move the data. That function existed in the code base already, but apparently wasn't used.

[Linkplay2020]

I have already modified this part of the code, so this change is no longer needed.