The parent directories of the identifier-registration.yaml config file might
not exist when starting idp. So instead of creating just the top most
directory use MkdirAll to also create the parents.
This switches the oidc implementation to libregraph/lico, which for now
is just a rename of kc/konnect. As there is no working lico release yet
(lico 0.34.0 wasn't fully renamed), we point it to the current master.