Add playlist-sync and group-wait to SyncPlay

MediaBrowser.Model/SyncPlay/GroupStateUpdate.cs

@@ -0,0 +1,22 @@
+#nullable disable
+
+namespace MediaBrowser.Model.SyncPlay
+{
+    /// <summary>
+    /// Class GroupStateUpdate.
+    /// </summary>
+    public class GroupStateUpdate
+    {
+        /// <summary>
+        /// Gets or sets the state of the group.
+        /// </summary>
+        /// <value>The state of the group.</value>
+        public GroupState State { get; set; }
+
+        /// <summary>
+        /// Gets or sets the reason of the state change.
+        /// </summary>
+        /// <value>The reason of the state change.</value>
+        public PlaybackRequestType Reason { get; set; }
+    }
+}