Fix the LinkedIn provider to invoke the CreatingTicket event and switch to the new LinkedIn API

Author: xperiandri

src/AspNet.Security.OAuth.LinkedIn/LinkedInAuthenticationDefaults.cs

@@ -36,12 +36,12 @@ public class LinkedInAuthenticationDefaults
         /// <summary>
         /// Default value for <see cref="OAuthOptions.AuthorizationEndpoint"/>.
         /// </summary>
-        public const string AuthorizationEndpoint = "https://www.linkedin.com/uas/oauth2/authorization";
+        public const string AuthorizationEndpoint = "https://www.linkedin.com/oauth/v2/authorization";
 
         /// <summary>
         /// Default value for <see cref="OAuthOptions.TokenEndpoint"/>.
         /// </summary>
-        public const string TokenEndpoint = "https://www.linkedin.com/uas/oauth2/accessToken";
+        public const string TokenEndpoint = "https://www.linkedin.com/oauth/v2/accessToken";
 
         /// <summary>
         /// Default value for <see cref="OAuthOptions.UserInformationEndpoint"/>.