Automatically detect MSVC tools on Windows interpreter

[HertzDevil]

Recreates the MSVC developer prompt environment so that the interpreter can be used outside such a prompt, similar to normal compilation.

[beta-ziliani]

Thanks Quinton! 🙇

EDIT: we need to wait for CI, but I sense there won't be issues here, as it's mostly a moving of code for the compiler, and a new thing for the interpreter.