Godot 4.2 / .net6 port

[Treer]

trafficstars

also addresses #104

~This PR might age like milk and need to be dropped as refinements continue in Godot 4, but today it works 😄~

Godot 4.0-stable only took minor tweaks from the initial Godot 4 Beta-16 pull request

[quentincaffeino]

Thank you, definitely better than nothing