flatpaksigner: Allow multiple application IDs for the KDE Runtime and for Okular
- To publish the runtime we need to bundle, sign and publish org.kde.Sdk and org.kde.Platform separately (but in the same repository) because a flatpak bundle can only contain a single "application".
- Okular comes in two flavors. The Kirigami-based version mainly targets mobile devices, but there might be people wanting to use Okular (as flatpak) on a Linux-based touch device. Both variants are published in the same repository.