Add OpenMSX deserialization test, fix issues

SabreTools.Models/OpenMSX/Original.cs

@@ -6,9 +6,22 @@ namespace SabreTools.Models.OpenMSX
     [XmlRoot("original")]
     public class Original
     {
-        [XmlElement("value")]
+        [XmlAttribute("value")]
         public bool Value { get; set; }
 
+        [XmlText]
         public string? Content { get; set; }
+
+        #region DO NOT USE IN PRODUCTION
+
+        /// <remarks>Should be empty</remarks>
+        [XmlAnyAttribute]
+        public XmlAttribute[]? ADDITIONAL_ATTRIBUTES { get; set; }
+
+        /// <remarks>Should be empty</remarks>
+        [XmlAnyElement]
+        public object[]? ADDITIONAL_ELEMENTS { get; set; }
+
+        #endregion
     }
 }