use native .NET json for JSON/BSON wz file extraction. (2-3x speed up)

versions < 150 should take less than 1 minute for JSON and BSON extraction

.NET 3.0 changes:
https://devblogs.microsoft.com/dotnet/try-the-new-system-text-json-apis/
.NET 5.0 changes:
https://devblogs.microsoft.com/dotnet/whats-next-for-system-text-json/

Author: lastbattle

MapleLib/MapleLib.csproj

@@ -15,6 +15,9 @@
     <AssemblyVersion>2.0.0.0</AssemblyVersion>
     <FileVersion>2.0.0.0</FileVersion>
   </PropertyGroup>
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <Optimize>False</Optimize>
+  </PropertyGroup>
   <ItemGroup>
     <ProjectReference Include="..\spine-runtimes-2.1.25\spine-csharp\spine-csharp 2.1.25.csproj" />
   </ItemGroup>