Fall back to well-known URL in client if 401 response is missing resource_metadata parameter (#1054)

tests/Common/Utils/LoggedTest.cs

@@ -16,12 +16,15 @@ public class LoggedTest : IDisposable
         LoggerFactory = Microsoft.Extensions.Logging.LoggerFactory.Create(builder =>
         {
             builder.AddProvider(XunitLoggerProvider);
+            builder.AddProvider(MockLoggerProvider);
+            builder.SetMinimumLevel(LogLevel.Debug);
         });
     }
 
     public ITestOutputHelper TestOutputHelper => _delegatingTestOutputHelper;
     public ILoggerFactory LoggerFactory { get; set; }
     public ILoggerProvider XunitLoggerProvider { get; }
+    public MockLoggerProvider MockLoggerProvider { get; } = new();
 
     public virtual void Dispose()
     {