Apply FnOps to noise modules

[Razaekel]

In the future I see that these structs could simply implement Fn(Input) -> Output, but we need to wait for these to be stabilized first.

I also think that we need an impl for Fn.

From #121.

I'd like to see a representative example first to give some guidance on implementation.

[brendanzab]

As discussed on #124, I'm wondering if we could simply have a Map module that takes a function that transforms the outputs of the previous module?