Implement OpenID Connect static clients
This implements static clients, which can be put in a different database
than the normal OpenID Connect data, so that they can be put into a configuration
file.
Signed-off-by: Patrick Uiterwijk <puiterwijk@redhat.com>
Reviewed-by: Pierre-Yves Chibon <pingou@pingoured.fr>
Reviewed-by: Howard Johnson <merlin@merlinthp.org>