Context

The reloading/invalidating SSO config mechanism was introduced in MGNLSSO-265, however it doesn't work due to the type check on the interface doesn't work https://git.magnolia-cms.com/projects/ENTERPRISE/repos/magnolia-sso/browse/magnolia-sso/src/main/java/info/magnolia/sso/config/Pac4jConfigProvider.java#99-105

Proposed solution

Some ideas we could do:

• The reloading logic can extracted out of the provider and explicitly injected into the target code 
• Split ConfigProvider into a ConfigReloader and ConfigProvider
• Completely isolate the reloading logic out of e.g. Pac4jConfigProvider : whenever a computed pac4j config is needed - one can just consult the SSOConfig provider and check if the last resolved sso config equals the currently provided (and if not - update/re-resolve pac4j)
• and all the resource origin listening logic can be concealed within sso provider itself