Rewrite JSON.NET with Span or Memory

[tonyqus]

I'd like to know if this library still accepts big PR in case the PR is about rewritting the whole library with Span or Memory. I know there is some performance gap between STJ and Newtonsoft.Json. I still love this library so well although a lot of developers start giving up this library and use STJ instead.

• STJ means a Microsoft owned JSON library.
• JSON.NET means a real community owned JSON library.

They are very different. Tbh, I'm not an expert of Span or Memory. But I can learn and consult some other expert developers in the community. Huge Text handling is one of advanced topic of .NET programming. I also encounter the issue while maintaining NPOI. It's about how to deal with LOH problem. I think it's a path I should pursue and conquer.

Let me know your thoughts, James.

You are one of my heros! The hero of .NET community who owns the top 1 ranking nuget library.

References
https://stackoverflow.com/questions/76540528/how-to-deserialize-system-memory-with-jsonconvert-deserializeobject-in-c-sharp

[tonyqus]

#1761