In Qt5 the palette was introduced in the Control object (part of Qt-
Quick-Controls-2).
In Qt6 this property was moved to the superclass 'Item'.
This means that we no longer need to refer to a control when using a
palette, every single thing in QtQuick is an Item, afterall.
This gives the dark-theme a make-over with better colors, more colors
coming from the palette and this makes the conceptual usage between the
mobile and desktop clients of colors to be in-line.
tomFlowee