[iOS] Add Translate button to text fields' context menu

[LouiseHsu]

In WWDC24, Apple announce the new Translation API https://developer.apple.com/documentation/Translation
This would enable adding the Translate option to the context edit menu, which was previously blocked by not being able to access the Translate API

Part of #107578

WWDC video: https://www.youtube.com/watch?v=MuIFhbHNmqA

[justinmc]

That's great that we have an API to do this now 👍

[jmagman]

This is a Swift-only API and would require engine support #144791
cc @cbracken

[cbracken]

This is a Swift-only API and would require engine support #144791 cc @cbracken

Thanks for the heads-up! Added a note to the Swift in Engine issue.