Add Emby support

[memen45]

Received this request per email. Please upvote if you'd like to see support for Emby media server in SubMusic!

Below an overview of feature support and implementation:

API docs: https://github.com/MediaBrowser/Emby/wiki

provider method	Emby API	description	Content-Type
ping	/System/Ping or /System/Info/Public	returns code 200	application/json
recordPlay	//Users/{UserId}/PlayedItems/{Id}	submit a play	application/json
getAllPlaylists	/Users/{UserId}/Items, paged, filtered	returns array of all playlists available for the user	application/json
getPlaylist	/Users/{UserId}/Items, paged, filtered on Id	returns an array of one playlist object with {id}	application/json
getPlaylistSongs	/Playlists/{Id}/Items	returns an array of songs on the playlist with {id}	application/json
getRefId	/Audio/{Id}/stream	returns a refId for a song by {id} (this downloads the song)	audio/*
getArtwork	/Items/{Id}/Images/{Type}	returns a BitmapResource for a song id (use backdrop)	image/*
getAllPodcasts	N/A	returns array of all podcasts available for the user	application/json
getPodcast	N/A	returns a podcast object with {id}	application/json
getEpisodes	N/A	returns array of episodes for podcast with {id}	application/json

[mmandolesi-g]

As an avid Garmin and Emby user, this would be super helpful.

[shad-lp]

Same here