Right now we can configure a logout URL in Horizon when the SSO is the only configured login method, using https://docs.openstack.org/horizon/latest/configuration/settings.html#websso-default-redirect-logout

However, there are customers who need to have multiple login methods configured, and still be able to redirect the user on logout to the right SSO logout page.

We need to be able to configure separate logout URL for each login method configured, and to remember in the user session which method was used to login, so that we can redirect to the correct URL on logout.