Investigate Unity and Unreal Engine integration

It would be nice if this was plug-and-play with Unity or Unreal Engine, perhaps as a package that people can download and use to get FMOD up and running quickly.

I imagine that Unreal Engine would invoke the native AoT methods defined in `src/CFlat.Application/Events` from a C++ environment, whereas Unity would maybe call the events from C#, just needing the native AoT dll files that are compiled when running `dotnet publish`.