Improve import statement handling in QJSEngine::evaluate

#include <QCoreApplication>
#include <QDebug>
#include <QTimer>
#include <QQmlEngine>

QString script = "\
.import 'file.js' as Test\n\
\n\
Test.someFunction('value')\n\
";

void test() {
    QQmlEngine *engine = new QQmlEngine(QCoreApplication::instance());

    QJSValue value = engine->evaluate(script);
    if (value.isError()) {
        qDebug() << value.toString();
    }
    qDebug() << value.toVariant();
    QCoreApplication::quit();
}

int main(int argc, char *argv[])
{
    QCoreApplication app(argc, argv);
    QTimer::singleShot(0, &app, &test);
    return app.exec();
}

// file.js

export var someVar = "blabla";

export function someFunction(someArg) {
    return someArg;
}