Make the library truly binary 🤪

[maximkrouk]

My proposal is to merge UIKit and AppKit navigation products into new CocoaNavigation with conditional exports and aliases

Since Cocoa is basically AppKit with a few additions and UIKit is basically CocoaTouch they fall under the same umbrella and it feels intuitive for me to combine them 💁‍♂️

If it makes sense to you I can open a PR, the change will be just additive, new target, new product. Old targets and products remain untouched (I like that the implementation is in 2 separate targets, it keeps things clean)