(Fix warning) Added missing annotation for new param in TokenRefreshedEventArgs (#370)

* Added Identity Token to TokenRefreshEventArgs

This change allows updating the identity token cached at the client with the latest identity token coming from token renewal

* Make Identity Token optional in TokenRefreshEventArgs to prevent breaking changes

* Added missing annotation for new param in TokenRefreshedEventArgs (fixes related warning)

Author: fmgracias

src/OidcClient/TokenRefreshedEventArgs.cs

@@ -17,6 +17,7 @@ public class TokenRefreshedEventArgs : EventArgs
         /// <param name="accessToken">The access token.</param>
         /// <param name="refreshToken">The refresh token.</param>
         /// <param name="expiresIn">The expires in.</param>
+        /// <param name="identityToken">The identity token (optional).</param>
         public TokenRefreshedEventArgs(string accessToken, string refreshToken, int expiresIn, string identityToken = null)
         {
             AccessToken = accessToken;