Add CHD version extension

Author: mnadareski

SabreTools.Serialization/Wrappers/CHD.cs

@@ -52,6 +52,25 @@ public byte[]? SHA1
             }
         }
 
+        /// <summary>
+        /// CHD version
+        /// </summary>
+        public int Version
+        {
+            get
+            {
+                return Model switch
+                {
+                    HeaderV1 => 1,
+                    HeaderV2 => 2,
+                    HeaderV3 => 3,
+                    HeaderV4 => 4,
+                    HeaderV5 => 5,
+                    _ => 0,
+                };
+            }
+        }
+
         #endregion
 
         #region Constructors