[BUG] User Management link returns 404

[viniciusdc]

Context

When accessing the User Management nav link, users are redirected to the wrong page; this is because the keycloak realm is still using the old hub-HPC name, while the nebari-superhub-theme expects the presence of the nebari as the realm name. This mismatch leads to an error when finding the page. a mistake on the page was not found

Value and/or benefit

User access to authentication-related tools on keycloak

Anything else?

Addressing this correctly requires reconfiguring the realm name on keycloak, which could lead to issues with already existing deployments.