Let the slide control the progress bar of the slide

[makeros]

Right now the progress bar percentage is calculated using request animation frame.
The problem is that when we have a video slide (especially a custom one) then for example we need to set the duration of the slide after the video is loaded and the duration is then known.
When for some reason the video is lagging or buffering, just stop/play the progress bar is not enough to calculate the progress properly.
That's why we would need the posibillity to provide in the slide configuration our own function which will set the progress manually (setting the percentage of the progress)

• provide a function in the slide configuration which can set the progress slide manually
• update the demo with new slide where by clicking on an slide item we can move the progress forward