Add option for generating bindings using marshaling

[lithiumtoast]

Use MarshalAs attribute for strings, arrays, etc. Don't use CString in this case in bindgen.

See Microsoft docs for an example tutorial: https://learn.microsoft.com/en-us/dotnet/standard/native-interop/tutorial-custom-marshaller?source=recommendations.

[shayded-exe]

It would be awesome to support the new C# 11 UTF-8 strings!

[lithiumtoast]

@shayded-exe UTF-8 strings has been done in #167

[lithiumtoast]

I believe at this time adding an option to generate bindings using specific marshalling or custom marshalling is not aligned to the goals of this project and thus won't be implemented by me directly. I am happy to leave this issue open and have other people submit a pull request if they want to.

Microsoft has some documentation on custom marshalling here https://learn.microsoft.com/en-us/dotnet/standard/native-interop/tutorial-custom-marshaller?source=recommendations.