Layout is always RTL when locale is RTL

Currently, if we set RTL locale, whole layout changes to RTL,
and there is no way to change the layout back to LTR.

in main.cpp, add following lines to set RTL locale.

    QLocale egyptian(QLocale::Arabic, QLocale::Egypt);
    QLocale::setDefault(egyptian);

and the main.qml looks like below

import QtQuick 2.12
import QtQuick.Window 2.2
import QtQuick.Controls 2.12

Window {
    visible: true
    width: 1280
    height: 720
    title: qsTr("Hello World")

    ProgressBar {
//        LayoutMirroring.enabled: false
        anchors.centerIn: parent
        indeterminate: true
    }
}

When you run the sampler above, you will find out there is no way to change layout back to LTR.

This is because QQuickControl::isMirrored() checks layout mirroring OR text locale.
If the locale is RTL, isMirrored() always returns true.

https://code.qt.io/cgit/qt/qtquickcontrols2.git/tree/src/quicktemplates2/qquickcontrol.cpp#n1289

bool QQuickControl::isMirrored() const
{
    Q_D(const QQuickControl);
    return d->isMirrored() || d->locale.textDirection() == Qt::RightToLeft;
}

FYI. This could be resolved by reverting https://codereview.qt-project.org/c/qt/qtquickcontrols2/+/143100