[C2] EntraID Enterprise App Provisioning / SCIM compatibility

[ywarnier]

Azure EntraID now offers provisioning from EntraID, meaning it can be configured to call external web services to update users automatically.

This is a nice move coming from EntraID as it reduces overall work (less CPU cycles means less environmental impact) to synchronize users between EntraID and Chamilo (historically it would require Chamilo to go fetch a list of all users and then compare them with the local users list to see if anything had changed.

As documented on https://learn.microsoft.com/en-us/entra/identity/app-provisioning/user-provisioning, EntraID supports different connectors, one of them being REST web services.

It also supports SCIM (System for Cross-domain Identity Management) which sounds like a nice standard to add to our portfolio. From looking to it for a few minutes, it looks like we could just modify slightly the User entity and UserHelper and add a few new API endpoint and be done with it.
It also looks like using REST requires you to provide a SCIM-compatible intermediate of some sort, so SCIM definitely seems to be the way to go.

A few screens from EntraID's pages to configure the provisioning method.

BT#23135