qt5-qttools lacks QML support

As seen in lupdate/main.cpp of the qttools package, the lupdate tool lacks QML support if QT_NO_QML is defined, which in turn in defined if qtHaveModule(qmldevtools-private) is false in lupdate/lupdate.pro.

Projects that utilize QML can then not use such an lupdate.

I'd therefore like to request that qt5-qtdeclarative-dev be added as a make dependency for qt5-qttools.

If meaningful, something like

touch /tmp/a.qml && ! /usr/lib/qt5/bin/lupdate /tmp/a.qml 2>&1 | grep 'Some files have been ignored due to missing qml/javascript support'

could be used for testing the QML support of lupdate.