Add SevenZip dependency and decompress utility

ModifiedMM (habeebweeb fork) compresses scene data with lzma.

src/MeidoPhotoStudio.Converter/MeidoPhotoStudio.Converter.csproj

@@ -17,4 +17,7 @@
   <ItemGroup>
     <ProjectReference Include="..\MeidoPhotoStudio.Plugin\MeidoPhotoStudio.Plugin.csproj" />
   </ItemGroup>
+  <ItemGroup>
+    <PackageReference Include="LZMA-SDK" Version="18.1.0" />
+  </ItemGroup>
 </Project>

src/MeidoPhotoStudio.Converter/Utility/LZMA.cs

@@ -0,0 +1,40 @@
+using System.IO;
+using SevenZip.Compression.LZMA;
+
+namespace MeidoPhotoStudio.Converter.Utility
+{
+    internal static class LZMA
+    {
+        public static MemoryStream Decompress(Stream inStream)
+        {
+            var outStream = new MemoryStream();
+
+            var properties = new byte[5];
+
+            if (inStream.Read(properties, 0, 5) != 5)
+                throw new("input .lzma is too short");
+
+            var decoder = new Decoder();
+
+            decoder.SetDecoderProperties(properties);
+
+            var outSize = 0L;
+
+            for (var i = 0; i < 8; i++)
+            {
+                var v = inStream.ReadByte();
+
+                if (v < 0)
+                    throw new("Can't Read 1");
+
+                outSize |= ((long)(byte)v) << (8 * i);
+            }
+
+            var compressedSize = inStream.Length - inStream.Position;
+
+            decoder.Code(inStream, outStream, compressedSize, outSize, null);
+
+            return outStream;
+        }
+    }
+}