Implement Keycloak Group Enumeration and Group Introspection

[ericof]

Fixes #42

[erral]

I am not sure whether this plugin is the place to implement the specifics for Keycloak group enumeration or pas.plugins.keycloakgroupenumeration would be a better place.

[ericof]

@erral Let me check how feasible it is to extract just the group support to a new package, meanwhile @mpeeters I wait for your feedback ;-)

[mpeeters]

@ericof I tried the new changes and I still have the same issue, my user have the groups and roles (listed in the Plone control panel), but those roles are not effective, and thus, my user does not have any related permissions (checked with manage_access)

Regarding performance, it is way better than before.

[ericof]

Interesting 🤔, I will double check what could be the issue with the roles not being applied

[ericof]

@erral, @mpeeters: Please take a look at the updated version -- that only mentions pas.plugins.keycloakgroups

[mamico]

Agreed about moving the functionality to a separate product.