One benefit here becomes immediately obvious - `flatpak_fail()` was lacking
`G_GNUC_PRINTF` which meant we missed a lot of type checking. Fix up the
callers.
This is a major change in the OCI support, as the format of the OCI image
registries changed. Instead of now having a "ref" file for each image
in the repo it has a single index json file, where the ref name is now
a per-image annotation.
This allows us to support OCI much better, as we can now use the actual
flatpak ref as the OCI ref name, and we can find all the flatpak refs
in a remote.
So, with this you can just use:
flatpak remote-add --oci remote-name URL
and then you can use the regular flatpak operations on the remote.
If the bundle contains an origin link we can now install related
things from it, such as locale data.
You can also build the bundle with --runtime-repo=URL, where the url
points to a flatpakrepo file for a repo with runtimes. This works
similar to the RuntimeRepo= feature in flatpakref files.
We juse use g_file_new_for_commandline_arg instead of g_file_new_for_path.
This is somewhat related to https://github.com/flatpak/flatpak/issues/401
but doesn't actually handle the specific case of tilde.