Changed repodb to store more information about the referrer needed for the referrers query
Signed-off-by: Laurentiu Niculae <niculae.laurentiu1@gmail.com>
UI can now make use of OCI artifacts and references using `Referrers` gQL query.
It returns a list of descriptors that refer on their `subject` field to another
digest.
Signed-off-by: Alex Stan <alexandrustan96@yahoo.ro>