It fits better than "view-barcode" from the icon theme. This also tests
using ForkAwesome icons via the custom icon engine. Unfortunately this
does not seem to work within the Plasmoid so far.
* FontAwesome uses a propritary build system so let's move to its fork
ForkAwesome similar to Syncthing
* See https://github.com/syncthing/syncthing/pull/5237
* Bundle the font file instead of having the SVGs directly within
Syncthing Tray's own repository
Loading the icon for the button from resources ceased to work (maybe when
switching to `PlasmaComponents3.ToolButton`). This change works around the
problem and the old icon no longer needs to be bundled.
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)
```
* Use the name as sorting criteria and fall back to the ID if there's no
name
* Use new SyncthingSortFilterDirectoryModel also for Plasmoid's filtering
* See https://github.com/Martchus/syncthingtray/issues/75
* 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
Specifying the with explicitely on every level seems to fix this. Not sure
whether it is the best solution but Qt 6 will likely mess up everything
anyways so let's not put further effort into the QML stuff at this point.