For instance, the NetworkManager Plasmoid uses these margins for its
ListView. It looks probably better than without margins (after removing
paddings with scroll page).
The following uses of QCC1/PlasmaComponents2 remain:
```
…/DetailView.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Menu and MenuItem
…/DevicesPage.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Menu and MenuItem
…/DirectoriesPage.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Menu and MenuItem
…/DownloadsPage.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Menu and MenuItem
…/FullRepresentation.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for vertical TabBar
…/RecentChangesPage.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Menu and MenuItem
…/TopLevelView.qml:import org.kde.plasma.components 2.0 as PlasmaComponents // for Highlight and DialogStatus.Closed (used with Menu and MenuItem)
```
* Support triggering actions via the context menu in the regular tray like
it is already possible in the Plasmoid
* Support copying via the context menu in the Plasmoid like it is already
possible in the regular tray
* Reduce repetition of coding patterns using templates