Add Haskell implementation

[wallymathieu]

Potential inspiration for implementation:

• https://github.com/aisamanra/s-cargot
• https://github.com/archambaultv/sexpresso
• http://blog.stermon.com/articles/2020/05/20/haskell-safe-json-bytestream-parser.html

Otherwise the SML implementation might serve well enough.