This adds Kodi-like semi-transparent overlay with current media title, hour and estimated time when video will end. The overlay is visible only on fullscreen mode.
Create volume button with popover instead of using GTK provided volume button.
Creating new button with only needed elements is more efficient then removing unneeded items from pre-made volume button. This should also increase performance a little when changing volume, because now we generate new icon only when a change is needed. In pre-made button icon is regenerated on each volume change.
