Update the styling of the Playlist Player

[TheCraigHewitt]

In order to have the playlist player match the styling of the "HTML5" player, let's update the options of that shortcode to allow for either the "compact" or the "default" player designs. We should make the new designs here the default display for the shortcode

https://support.castos.com/hc/en-us/articles/360018867440-podcast-playlist-Shortcode includes the current parameters of the shortcode. I would like to add in another parameter that could be type with options for compact or default