washingMachineUI: fixes in the .qmlproject for MCUs

Task-number: QDS-9838

Looks and works fine (tested in DS with .qmlproject and QtCreator with CMakeLists.txt). All that remains are console warnings:

C:/git/dev/qtdesign-studio/examples/washingMachineUI/Washprogramsettings.qml:118:13: warning: Implicitly defined onFoo properties in Connections are deprecated. Use this syntax instead: function onFoo(<arguments>) { ... }
            onClicked: {
            ^~~~~~~~~

I have noticed that designer in the Design Studio generates slots using the old syntax, so changing the syntax manually seems pointless at the moment. I don't see any option to mute them in the qmlprojectexporter.