This commit clarifies and points out that the Role management UI and
the Role management API cannot be used to manage roles that are
defined in roles.yml and that file based role management is
intended to have a small administrative scope and not handle all
possible RBAC use cases.
* This commit is part of our plan to deprecate and ultimately remove the use of _xpack in the REST APIs.
- REST API docs
- HLRC docs and doc tests
- Handle REST actions with deprecation warnings
- Changed endpoints in rest-api-spec and relevant file names
