Fix registration

[longshuicy]

Ready to be reviewed.

• Turns out not only "redirect_uri" is needed
• but also "scope" is needed as well.
• Also I realized the production docker-compose is still using keycloak 19 --> updated to 20 now
• Might be related to the change we made in this past PR: https://github.com/clowder-framework/clowder2/pull/897/files

To Test:

1. docker compose up and use follow registration link on the topbar as usual
2. Since it's only the redirect uri, you can also test the k8s cluster:
   • Go to https://clowder2.software-dev.ncsa.illinois.edu/auth/register
   • In the redirected url append &scope=openid%20email
   • Alternatively, you can directly paste the link to browser: https://clowder2.software-dev.ncsa.illinois.edu/keycloak/realms/clowder/protocol/openid-connect/registrations?client_id=clowder2-backend&response_type=code&redirect_uri=http://clowder2.software-dev.ncsa.illinois.edu/api/v2/auth&scope=openid%20email
   • Register and see if it works

[ddey2]

works now.