Ability to compile files at REPL

[yumaikas]

At the REPL, I'd like to be able to fire off the GDLisp compiler against files. use is the closest thing to this, but it complains if I try to use the same file twice.

The main thing I'm trying to avoid here is the cost of launching Godot each compilation using the GDLisp cli. I don't conceptualize this as an eval replacement, at least for now.