Add ErrorDescription to result of RefreshTokenAsync error

src/OidcClient.cs

@@ -320,7 +320,11 @@ public virtual async Task<RefreshTokenResult> RefreshTokenAsync(string refreshTo
 
             if (response.IsError)
             {
-                return new RefreshTokenResult { Error = response.Error };
+                return new RefreshTokenResult
+                {
+                    Error = response.Error,
+                    ErrorDescription = response.ErrorDescription,
+                };
             }
 
             // validate token response

src/Results/Result.cs

@@ -24,5 +24,13 @@ public abstract class Result
         /// The error.
         /// </value>
         public virtual string Error { get; set; }
+
+        /// <summary>
+        /// Gets or sets the error description.
+        /// </summary>
+        /// <value>
+        /// The error description.
+        /// </value>
+        public virtual string ErrorDescription { get; set; }
     }
-}
+}