Add support for custom full screen

[dipanshparmar]

I've this use case where I want to define the custom fullscreen functionality for the video. So when a video goes to full screen, I want to use my custom page to show the video where the user can scroll vertically to see more videos. This is not possible with the current chewie configuration. So can we provide a different functionality when clicking the full screen icon? Currently I'm doing this by creating a custom option in the thee dots.