* Avoid use of deprecated QML features
* Fix problems when moving items by making the delegates own items
* Improve code in models, especially functions for moving rows
* Fix sizing of dialogs
* Replace code relying on `bannerClicked` event which has been removed in
KF6
* Use the native file dialog if supported (and otherwise not); this should
give the desired behavior under each platform out of the box
* Update versioning requirements in README
