iostool: Cleanup and improve debug output

Replaced the custom command line arg parsing code
with QCommandLineParser

Change-Id: I14e8695b5ee327b1d111558271bf98afd0c942b0
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>

src/plugins/ios/iostoolhandler.cpp

@@ -733,7 +733,7 @@ void IosDeviceToolHandlerPrivate::requestRunApp(const QString &bundlePath,
         args << QLatin1String("--debug");
         break;
     }
-    args << QLatin1String("--args") << extraArgs;
+    args << QLatin1String("--") << extraArgs;
     op = OpAppRun;
     start(IosToolHandler::iosDeviceToolPath(), args);
 }