Debugger: Also log time stamp when handling output is finished

This helps to put the blame properly on either side of the
communication.

Change-Id: Id83de2bce1984f63427f655dce854ebb008a1a61
Reviewed-by: David Schulz <david.schulz@qt.io>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/debugger/gdb/gdbengine.cpp

@@ -410,6 +410,9 @@ void GdbEngine::handleResponse(const QString &buff)
             break;
         }
     }
+
+    if (debuggerSettings()->logTimeStamps.value())
+        showMessage(QString("Output handled"));
 }
 
 void GdbEngine::handleAsyncOutput(const QStringView asyncClass, const GdbMi &result)