Update SDK to ASWebAuthenticationSession from SFAuthenticationSession for iOS 12.0

The iOS SDK Still uses the SFAuthenticationSession

which is deprecated by Apple, shall we get the ASWebAuthenticationSession in iOS SDK for iOS 12 devices?

Thanks

Hey there @MuraliKathir

I think it will be better to address this issue directly in appropriate GitHub repo tagging repo maintainers to see this as this will give you and whole community faster response and reaction to this.

Thank you!