Added Spotify playlist event

[StijnOostdam]

Please also test the functionality very carefully

[StijnOostdam]

2020-03-18 07:56:48.8462|WARN|Winleafs.Wpf.Api.Events.SpotifyEventTrigger|Retrieving the Spotify current playlist failed.
System.ArgumentException: An item with the same key has already been added. Key: System.Net.Http.Headers.HeaderDescriptor
   at System.Collections.Generic.Dictionary`2.TryInsert(TKey key, TValue value, InsertionBehavior behavior)
   at System.Collections.Generic.Dictionary`2.Add(TKey key, TValue value)
   at System.Net.Http.Headers.HttpHeaders.GetOrCreateHeaderInfo(HeaderDescriptor descriptor, Boolean parseRawValues)
   at SpotifyAPI.Web.SpotifyWebClient.AddHeaders(Dictionary`2 headers)
   at SpotifyAPI.Web.SpotifyWebClient.DownloadRawAsync(String url, Dictionary`2 headers)
   at SpotifyAPI.Web.SpotifyWebClient.DownloadAsync(String url, Dictionary`2 headers)
   at SpotifyAPI.Web.SpotifyWebClient.DownloadJsonAsync[T](String url, Dictionary`2 headers)
   at SpotifyAPI.Web.SpotifyWebAPI.DownloadDataAsync[T](String url)
   at Winleafs.Wpf.Helpers.Spotify.GetCurrentPlayingPlaylist() in Winleafs\Winleafs.Wpf\Helpers\Spotify.cs:line 63
   at Winleafs.Wpf.Api.Events.SpotifyEventTrigger.CheckPlaylistAsync() in Winleafs\Winleafs.Wpf\Api\Events\SpotifyEventTrigger.cs:line 54

[StijnOostdam]

Exception fixed, I want to add a message on startup whether the spotify client is connected or not.

EDIT: done

[bartdebever]

• Even thought there aren't many options, we should put this on a Spotify tab in the options.
• Make the connect button only available when disconnected and vise versa.
• Connect and Disconnect should both be capital S in Spotify

[bartdebever]

Have a dropdown that contains the playlists that the user has instead of putting in the name.

[StijnOostdam]

Also should add a message saying that it is only available to premium Spotify users due to API limitations

[StijnOostdam]

Access token only seems valid for a few hours