Moving JSON serialization code to dedicated libraries

[MovGP0]

• Moving code that is dependent on System.Text.Json and Newtonsoft.Json to dedicated libraries
• Switching from Newtonsoft.Json to System.Text.Json for ASP.NET binder
• Fixing all unit tests

Open issues

• Update documentation.
  • Because the serialization attributes are now missing, a dedicated registration for the JsonConverters is required
  • Additonal NuGet packages must be added when serialization is required
• Update version number because of breaking change

[kyleherzog]

Thanks for your interest in this project. This is super intriguing. Here are some initial impressions.

• Splitting out the System.Text.Json serialization support makes complete sense. I'm a huge fan of this.
• Splitting out the Newtonsoft serialization is a big breaking change. I'm personally involved in a large number of private projects that would be impacted by this. Not only it is breaking but it adds a layer of friction by having to configure the serializer. I understand the advantage of not having the Newtonsoft dependency though. I wonder if there is some other creative way to keep the current ease of use for those using Newtonsoft and still allow for those that don't want the dependency.
• For the ASP.net binding, it feels like there should be two separate packages, one for Newtonsoft and one for System.Text.Json. This would allow for people to choose what they want to use.