Add explicit string wrapping system

[isaiahshiner]

In general, passing strings back from GuestLangs is very inconsistent and confusing. It works, but it's very tedious.

If you do <|return (|out|)|> it will treat out literally, as though you want to execute out as dit code.
You can wrap it like <|return '(|out|)'|> but this is confusing and causes issues with quote characters inside the string.

I'm not sure how to solve this, but I'm sure there's a reasonable solution that's better than what we have now. It's probably something like <|return literal((|out|))|>, where literal is a built_in function that wraps the string.