Added SSO flows and functionality (#1047)

* SSO login flow for pre-existing user and no 2FA

* 2FA progress

* 2FA support

* Added SSO flows and functionality

* Handle webauthenticator cancellation gracefully

* updates & bugfixes

* Added state validation to web auth response handling

* SSO auth, account registration, and environment settings support for iOS extensions

* Added SSO prevalidation to auth process

* prevalidation now hitting identity service base url

* additional error handling

* Requested changes

* fixed case

src/iOS/AppDelegate.cs

@@ -241,6 +241,15 @@ namespace Bit.iOS
             return true;
         }
 
+        public override bool OpenUrl(UIApplication app, NSUrl url, NSDictionary options)
+        {
+            if (Xamarin.Essentials.Platform.OpenUrl(app, url, options))
+            {
+                return true;
+            }
+            return base.OpenUrl(app, url, options);
+        }
+
         public override void FailedToRegisterForRemoteNotifications(UIApplication application, NSError error)
         {
             _pushHandler?.OnErrorReceived(error);