RBAC for Analytics entities

While there is fine-grained access control on entities in the Data Service (buckets, scopes, collections) it is currently not possible to directly control access to Analytics entities (dataverses/scopes, datasets/collections, ..). The requirement is to grant users access to particular Analytics collections without giving the users access to the underlying bucket or to all collections.

Couchbase users should be able to control access to all analytics entities.

This improvement was originally targeted for 7.0.0, the PRD doc for 7.0.0 is here:
https://docs.google.com/document/d/1CEFK3vexGoKF0FhvPmIjUoz4aBAWTWsWIzhUXmHvYi4/edit?usp=sharing