Feature request: Allow for a callback for swipe back gesture on iOS

[RayKay91]

Sometimes we want to do something before the user goes back, which can usually be handled with the onBeforeRemove event in React-Navigation but this doesn't support swipe gestures on the iOS.

We could use the interactivePopGestureRecognizer to try and achieve a callback where we can handle logic as the user does a swipe-to-go-back.

https://developer.apple.com/documentation/uikit/uinavigationcontroller/interactivepopgesturerecognizer

https://stackoverflow.com/questions/32005718/is-there-any-callback-for-swipe-back-gesture-in-ios/32007026

[kkafar]

Yeah, I guess it does make sense. I'll put this on our internal board.

The prevent-remove mechanism in native stack requires overhaul anyway.