Distinguish between when the user declined the "Sign In" prompt or cancelled the flow in iOS

The issue https://github.com/FormidableLabs/react-native-app-auth/issues/565 suggests a way to differentiate between cancels from login failures.

But in iOS there are two types of cancellations in general:
1. when the user presses "Cancel" on the prompt, that is by declining to sign in itself which is before the browser flow is even started
2. when the user actually cancels the login flow or closes the browser

Is there anyway to distinguish between these two cases for iOS? For proper tracking purposes, I'd like to know when the user declines the prompt specifically.

Currently if you check the `error` as per suggested in [here](https://github.com/FormidableLabs/react-native-app-auth/issues/565#issuecomment-1036596709), both of these cases resolve to user cancellation which is based on this [-3 error code](https://github.com/openid/AppAuth-iOS/blob/e191b1beadf3041259652e6e464eaceff16e5fbb/Source/AppAuthCore/OIDError.h#L103).

Comienza revisando la discusión sobre la cancelación en el issue 565 y el código de error referenciado de AppAuth-iOS Source/AppAuthCore/OIDError.h. Determina si las dos rutas de cancelación de iOS exponen señales distintas a través del puente de React Native; se considera completado cuando los llamadores pueden distinguir de forma fiable entre rechazar el aviso de Sign In y cancelar o cerrar el flujo del navegador.

Escrito por el modelo de indexación a partir del texto del issue.