Prefix many ostree error messages
Prefix many ostree error messages

Some of the ostree error messages don't contain sufficient detail
to be useful, so use g_prefix_error to add some context.

thiblahute/xdg-app,handsome-feng/flatpak,GeorgesStavracas/flatpak,alexlarsson/xdg-app,thiblahute/xdg-app,GeorgesStavracas/flatpak,amigadave/flatpak,handsome-feng/flatpak,matthiasclasen/flatpak,matthiasclasen/flatpak,chergert/xdg-app,chergert/xdg-app,matthiasclasen/flatpak,handsome-feng/flatpak,GeorgesStavracas/flatpak,GeorgesStavracas/flatpak,chergert/xdg-app,flatpak/flatpak,thiblahute/xdg-app,chergert/xdg-app,flatpak/flatpak,matthiasclasen/flatpak,matthiasclasen/xdg-app,flatpak/flatpak,matthiasclasen/xdg-app,handsome-feng/flatpak,handsome-feng/flatpak,flatpak/flatpak,GeorgesStavracas/flatpak,amigadave/flatpak,amigadave/flatpak,alexlarsson/xdg-app,matthiasclasen/xdg-app,alexlarsson/xdg-app,matthiasclasen/xdg-app,alexlarsson/xdg-app,flatpak/flatpak,thiblahute/xdg-app,amigadave/flatpak,matthiasclasen/flatpak