The formatter implementation from Microsoft.Extensions.Logging.Logger…

…Extensions class is ignoring the exception object and the exception information is not saved into log file. see the existing implemetation from below. (#1827)

Added handling for situation when the exception is not null and reused the existing code for formatting exceptions.

Stack/Opc.Ua.Core/Types/Utils/Utils.cs

@@ -557,6 +557,10 @@ public static void Trace<TState>(TState state, Exception exception, int traceMas
                 // append process and timestamp.
                 message.AppendFormat(CultureInfo.InvariantCulture, "{0:d} {0:HH:mm:ss.fff} ", DateTime.UtcNow.ToLocalTime());
                 message.Append(formatter(state, exception));
+                if (exception != null)
+                {
+                    message.Append(TraceExceptionMessage(exception, String.Empty, null));
+                }
             }
             catch (Exception)
             {