Simplify utility type

[jasonkuhrt]

When working with type computation, it is generally useful to use a "simplify" type utility to compute the final result so that e.g. IDEs show something more useful to end-users.

Example: https://github.com/sindresorhus/type-fest/blob/main/source/simplify.d.ts

It would be nice if Hotscript ships with its own version, as such a utility is often needed for the kinds of complex use-cases one would reach for Hotscript for.