Define a map function (like for, but non-monadic)

[RyanGlScott]

Currently, SAWScript offers a for function for iterating over a list in a monadic fashion:

for : {m, a, b} [a] -> (a -> m b) -> m [b]

For many use cases, however, it would be more convenient to iterate over a list without needing a monad m. For these scenarios, we should offer a map function:

map : {a, b} (a -> b) -> [a] -> [b]

SAWScript does not currently offer this, but it could easily be added.

[sauclovian-g]

FWIW, you can find here a bunch of other list ops needed on another project that are (AFAIK) not and maybe should be in the standard library.