VLCNowPlayingTemplateObserver: Display the queue instead of skipping to the next media

This merge request brings improvements to the Now Playing screen of the CarPlay interface with:

• The button at the top-right hand corner now displays the medias next in queue instead of skipping to the next media at it is described in the documentation.
• The play queue is also updated according to the shuffle state.

According to the nowPlayingTemplateUpNextButtonTapped method documentation:

When CarPlay calls this method on your observer, you should push an instance of CPListTemplate—other template
types are not supported when Now Playing is the visible template—on to your navigation stack that displays a
list of upcoming or queued content.