feat(batch4-task2): implement core logger wiring features

dotnet/src/ZB.MOM.NatsNet.Server/Internal/NatsLogger.cs

@@ -215,6 +215,8 @@ public sealed class MicrosoftLoggerAdapter : INatsLogger
 
     public MicrosoftLoggerAdapter(ILogger logger) => _logger = logger;
 
+    internal ILogger UnderlyingLogger => _logger;
+
     public void Noticef(string format, params object[] args) =>
         _logger.LogInformation(format, args);