Changes:
- Distribute extra empty space between offsets and xdisp (Rok Mandeljc)
- Improve border with calculations (Ryan Koesters)
- Migrate build system to meson (Martin Blanchard)
- Add OARS metadata (nick richards)
- Update various links after bugzilla to gitlab migration (Andre Klapper, Piotr Drąg)
- Rename icons, appstream and desktop files to consistently use org.gnome.GHex ID (Bilal Elmoussaoui)
- Add flatpak manifest for nightly builds, enable nightly builds in CI (Bilal Elmoussaoui)
- Install appstream metadata to non-deprecated location (Jeremy Bicha)
- Various updates to help docs (Andre Klapper, Piotr Drąg)
