Revert "revert to basic multi-result passing from function"

This reverts commit 3bf8afe5.

alib2gui/src/Graphics/Dialogs/OutputDialog.cpp

@@ -48,12 +48,7 @@ void OutputDialog::hideTab(QWidget* tab) {
 }
 void OutputDialog::on_saveBtn_clicked() {
-//    auto [filter, extension] = this->getCurrentTabFileFilter(); //FIXME use when g++ on gitlab-ci supports it
-
-    std::pair<QString, QString> res = this->getCurrentTabFileFilter();
-    QString filter = res.first;
-    QString extension = res.second;
-
+    auto [filter, extension] = this->getCurrentTabFileFilter();
     QString filename(QFileDialog::getSaveFileName(this,
                                                   tr("Save file"),
                                                   QDir::homePath(),