fix: add antergos-wallpapers to rootfs packages, restore Install Artix hide

- antergos-wallpapers now installed into rootfs so the KDE wallpaper picker
  shows the Antergos wallpaper automatically (package installs to
  /usr/share/wallpapers/antergos-wallpaper/ with metadata.desktop).
- Restored calamares-config-switcher.desktop in live-overlay with
  NoDisplay=true to hide 'Install Artix' from the app menu. Previous deletion
  exposed the package version, making it visible again.

iso-profiles/antergos/profile.yaml

@@ -92,6 +92,7 @@ rootfs:
     - calamares-branding-antergos-next
     - antergos-welcome
     - antergos-next-memes
+    - antergos-wallpapers
     - hiredis
     - libdbi
     - libesmtp