OnPageLoading and OnPageLoaded functions are not called from WKWebViewUIDelegate

[Abhirasmanu-Trimble]

Xamarin.Auth Issue

IF BUG, INCLUDE THIS PART:

Version

• nuget version = 1.7.0
• component version =
• sample

Steps to reproduce

1. Set Xamarin.Auth.WebViewConfiguration.IOS.IsUsingWKWebView = true;
2. Use implicit login for logging in
3. After successfull login WebAuthenticator.OnPageLoaded is not called and hence redirect url is not processed

Platform:

• [] .NET version = 7.3
• [] mono version = 6.0.0.327

Expected behaviour

OnPageLoaded should be called with Redirect URL

Actual behaviour

Redirect URL after Successfull login should be processed

[Abhirasmanu-Trimble]

Below pull request have fixes for this issue.
#413