add volume

Azaion.Annotator/DTO/FormState.cs

@@ -10,7 +10,8 @@ public class FormState
     public string CurrentFile { get; set; } = null!;
     public Size CurrentVideoSize { get; set; }
     public string VideoName => Path.GetFileNameWithoutExtension(CurrentFile).Replace(" ", "");
-    public TimeSpan CurrentVideoLength { get; set; }    
+    public TimeSpan CurrentVideoLength { get; set; }
+    public int CurrentVolume { get; set; } = 100;
 
     public string GetTimeName(TimeSpan ts) => $"{VideoName}_{ts:hmmssf}";
 }

Azaion.Annotator/DTO/MediatrEvents.cs

@@ -13,3 +13,8 @@ public class PlaybackControlEvent(PlaybackControlEnum playbackControlEnum) : INo
 {
     public PlaybackControlEnum PlaybackControl { get; set; } = playbackControlEnum;
 }
+
+public class VolumeChangedEvent(int volume) : INotification
+{
+    public int Volume { get; set; } = volume;
+}

Azaion.Annotator/DTO/PlaybackControlEnum.cs

@@ -10,5 +10,7 @@ public enum PlaybackControlEnum
     NextFrame = 5,
     SaveAnnotations = 6,
     RemoveSelectedAnns = 7,
-    RemoveAllAnns = 8
+    RemoveAllAnns = 8,
+    TurnOffVolume = 9,
+    TurnOnVolume = 10
 }