Extend QQC2 controls into Kirigami
I think that many QQC2 components can be extended into Kirigami so that we can add functionality.
Since we are not reimplementing components, we can instead choose QQC2 components to extend instead so that it does not require as much maintenance.
This can provide solutions to problems like providing consistent context menus, as there is no way to provide consistent textfield context menus right now (the current solution is in qqc2-desktop-style, which causes applications that have their own context menu to show up with 2).