Missing packages for Rest API

[martinfreedman]

Some use Newtonsoft.Json but the majority of solutions use FSharp.Data/FSharp.Data.JsonExtensions or FSharp.Json and there might be other standard libraries.

These should be added to the TestRunner default packages.

[ErikSchierboom]

Maybe also include https://thoth-org.github.io/Thoth.Json?

[martinfreedman]

Yes!