flatpak: Allow using newer appstream API to look up by bundle id
This way we don't need to create and loop through every component.
Test Cases:
plasma-discover --backends flatpak https://dl.flathub.org/repo/appstream/com.dosbox.DOSBox.flatpakref
-
./bin/flatpaktest testInstallFlatpakref
(faster) ./bin/flatpaktest
Draft because it's not working on my system, for some reason appstream gives me 0 components with the new code path.
Edited by Aleix Pol Gonzalez