Review/Rewrite Users, Groups and Orgs cache behaviors

Will be groomed/finalised after investigation ticket NXS-6473

We lost track of what/where users/group caches are required and the history why they exist.
And it started to be very hard to touch them, without unpredictable impacts and not-tested side effects. We also need to review the benefits of those custom cache on virtual groups compared with the principalCache implemented by default with the UserManager.

Especially we will soon be able to rely on ElasticSearch for improving some queries.

Entry points to review/rewrite:

• com.nuxeo.connect.service.NuxeoConnectComponent#namesCache
• com.nuxeo.connect.security.cache.ComputedGroupCacheComponent
• com.nuxeo.connect.security.OrgIdGroupComputer
• org.nuxeo.ecm.platform.usermanager.UserManagementImpl#principalCache

Goal:

• Better understand why they were initially created
• Define Action plan: Remove&Monitor? Rewrite Code? ElasticSearch?
• Ideally, fix those caches.