read track from music video nfo metadata (#799)

ErsatzTV.Core/Metadata/Nfo/MusicVideoNfo.cs

@@ -17,6 +17,9 @@ public class MusicVideoNfo
     [XmlElement("plot")]
     public string Plot { get; set; }
 
+    [XmlElement("track")]
+    public int Track { get; set; }
+
     [XmlElement("aired")]
     public Option<DateTime> Aired { get; set; }
 

ErsatzTV.Core/Metadata/Nfo/MusicVideoNfoReader.cs

@@ -72,6 +72,9 @@ public class MusicVideoNfoReader : NfoReader<MusicVideoNfo>, IMusicVideoNfoReade
                             case "plot":
                                 await ReadStringContent(reader, nfo, (musicVideo, plot) => musicVideo.Plot = plot);
                                 break;
+                            case "track":
+                                await ReadIntContent(reader, nfo, (musicVideo, track) => musicVideo.Track = track);
+                                break;
                             case "year":
                                 await ReadIntContent(reader, nfo, (musicVideo, year) => musicVideo.Year = year);
                                 break;