Qt 编写的qml程序全屏时，挡住系统虚拟键盘的解决办法

官方有提到该问题。尤其是使用qml时，一定会出现这个遮挡问题。
https://doc.qt.io/qt-5/windows-issues.html

 默认的qml工程的解决代码如下：

...
#include <QWindow>
#include <QtPlatformHeaders/QWindowsWindowFunctions>
...

int main(int argc, char *argv[])
{
...
    QQmlApplicationEngine engine;
    const QUrl url(QStringLiteral("qrc:/qml/main.qml"));
    QObject::connect(&engine, &QQmlApplicationEngine::objectCreated,
                     &app, [url](QObject *obj, const QUrl &objUrl) {
        if (!obj && url == objUrl)
            QCoreApplication::exit(-1);
    }, Qt::QueuedConnection);
    engine.load(url);
    
    auto tlwWindow = (QWindow*)engine.rootObjects().first();
    QWindowsWindowFunctions::setHasBorderInFullScreen(tlwWindow, true);
...
}