Requires qml
Possible tasks:
[x] replace the custom search field in the NavigationActionBar with the `Kirigami.SearchField` component
[x] implement a busy indicator for the `Kirigami.InlineMessage` and replace Elisa's TrackImportNotification
[ ] port MetaDataView and ContextView to `Kirigami.FormLayout`
[ ] port main window to `Kirigami.ApplicationWindow`
[ ] port toolbars with actions on them to `Kirigami.ActionToolBar`