[Feature] Replace Newtonsoft.Json with System.Text.Json

[CodingOctocat]

If possible, this will make the project 0 dependent.

[mircea21S]

Hey!

That would be great, but I am afraid System.Text.Json is not supported directly on .NET framework 4.8 or lower. RichCanvas is supporting these frameworks as well.

I would need to add the System.Text.Json Nuget package to work with .NET framework which basically doesn't change much.

Might consider this in the future. This is used for UI Automation, so if improvements will come in the future, might ditch the JSON usage altogether.