Add a locale property to validators

QIntValidator and QDoubleValidator support locale specific validation but there is no way to change the locale used from QML.

IntValidator and DoubleValidator should have a property for setting this which takes a takes either a locale string or object.

Something like:

IntValidator {
    locale: Qt.locale("de_DE")
}

Or possibly just:

IntValidator {
    locale: "de_DE"
}