Add ClrMamePro deserialization test, fix issues

SabreTools.Models/ClrMamePro/GameBase.cs

@@ -0,0 +1,42 @@
+namespace SabreTools.Models.ClrMamePro
+{
+    /// <summary>
+    /// Base class to unify the various game-like types
+    /// </summary>
+    public abstract class GameBase
+    {
+        /// <remarks>name</remarks>
+        public string? Name { get; set; }
+
+        /// <remarks>description</remarks>
+        public string? Description { get; set; }
+
+        /// <remarks>year</remarks>
+        public string? Year { get; set; }
+
+        /// <remarks>manufacturer</remarks>
+        public string? Manufacturer { get; set; }
+
+        /// <remarks>category</remarks>
+        public string? Category { get; set; }
+
+        /// <remarks>cloneof</remarks>
+        public string? CloneOf { get; set; }
+
+        /// <remarks>romof</remarks>
+        public string? RomOf { get; set; }
+
+        /// <remarks>sampleof</remarks>
+        public string? SampleOf { get; set; }
+
+        /// <remarks>release, biosset, rom, disk, media, sample, archive</remarks>
+        public ItemBase[]? Item { get; set; }
+
+        #region DO NOT USE IN PRODUCTION
+
+        /// <remarks>Should be empty</remarks>
+        public string[]? ADDITIONAL_ELEMENTS { get; set; }
+
+        #endregion
+    }
+}