Add MXF Decoder and MXF font test scene

Assets/Scripts/OpenTS2/Engine/Tests/MXFFontTest.cs

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+using OpenTS2.Files;
+using OpenTS2.Files.Formats.Font;
+using OpenTS2.UI.Skia;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using UnityEngine;
+
+namespace OpenTS2.Engine.Tests
+{
+    public class MXFFontTest : MonoBehaviour
+    {
+        public string BaseGameFontToUse = "";
+        public SkiaLabel Label;
+
+        private void Awake()
+        {
+            var baseGamePath = Filesystem.GetDataPathForProduct(Content.ProductFlags.BaseGame);
+            var fontPath = Path.Combine(baseGamePath, $"Res/UI/Fonts/{BaseGameFontToUse}");
+            var mxf = new MXFFile(fontPath);
+            var font = new SkiaFont(mxf.DecodedData);
+            Label.Font = font;
+        }
+    }
+}

Assets/Scripts/OpenTS2/Files/Formats/Font/MXFFile.cs

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+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.IO;
+using UnityEngine;
+
+namespace OpenTS2.Files.Formats.Font
+{
+    /// <summary>
+    /// Decodes Maxis font files (*.mxf), usually a wrapper for *.ttf or *.pfb fonts.
+    /// </summary>
+    public class MXFFile
+    {
+        public byte[] DecodedData { get; private set; }
+
+        public MXFFile(string filename)
+        {
+            var fstream = new FileStream(filename, FileMode.Open);
+            var reader = new BinaryReader(fstream);
+
+            var magic = reader.ReadBytes(4);
+            if (magic[0] != 77 || magic[1] != 88 || magic[2] != 70 || magic[3] != 78)
+                throw new IOException("Not a valid Maxis Font File!");
+
+            reader.ReadInt32();
+            var mask = reader.ReadByte();
+            var len = fstream.Length;
+            var memstream = new MemoryStream();
+            var writer = new BinaryWriter(memstream);
+            while (fstream.Position != len)
+            {
+                writer.Write((byte)(reader.ReadByte() ^ mask));
+            }
+            writer.Flush();
+            DecodedData = memstream.ToArray();
+            writer.Dispose();
+            memstream.Dispose();
+            reader.Dispose();
+            fstream.Dispose();
+        }
+    }
+}