Add option to require SAML/SSO authentication

At the moment, even if you enable authentication, users are still able to log in with other authentication options defined in the authentication settings page (which include: allow all, email and password, Google, Microsoft). Usually when enabling SSO, you do not want to allow authentication via any other means, as companies rely on the security controls enforced by their SSO/IdP.

So the request is to add an option for: OIDC/SAML/SSO, to be able to only accept authentication via that path.