Support Inf and NaN in models

[hhaensel]

trafficstars

Currently, Inf and NaN cannot be transmitted through JSON although javascript natively supports Infinity and NaN.

This issue relates to https://github.com/GenieFramework/StippleUI.jl/issues/135

I've submitted a PR to JSON3, that would make adaptation much easier, let's see whether they like it. https://github.com/quinnj/JSON3.jl/issues/292