Add new CMP test file, fix issues

SabreTools.Models/ClrMamePro/Sound.cs

@@ -0,0 +1,16 @@
+namespace SabreTools.Models.ClrMamePro
+{
+    /// <remarks>sound</remarks>
+    public class Sound
+    {
+        /// <remarks>channels, Numeric?</remarks>
+        public string Channels { get; set; }
+
+        #region DO NOT USE IN PRODUCTION
+
+        /// <remarks>Should be empty</remarks>
+        public object[]? ADDITIONAL_ELEMENTS { get; set; }
+
+        #endregion
+    }
+}