Add Identifiable proposal (#1057)
Add Identifiable proposal (#1057)

* Add Identifiable proposal

* Launch review

* Make proposal UI-framework-agnostic

* Tweak title

natecook1000/swift-evolution,abertelrud/swift-evolution,Nirma/swift-evolution,natecook1000/swift-evolution,abertelrud/swift-evolution,apple/swift-evolution,Nirma/swift-evolution,hartbit/swift-evolution,apple/swift-evolution,hartbit/swift-evolution