Use qAsConst with non-const Qt containers in range-loops

... in various places

Change-Id: Ic6c0c1b9437a1ed402105c7a14a1f5f9454a68d4
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

src/plugins/qmlpreview/qmldebugtranslationwidget.cpp

@@ -368,7 +368,7 @@ void QmlDebugTranslationWidget::runTest()
                 });
             }
         };
-        for (auto filePath : m_selectedFilePaths) {
+        for (auto filePath : qAsConst(m_selectedFilePaths)) {
             testLanguages(timerCounter++, filePath.toString());
         }
     });