Recommend use of Application Credentials

[berendt]

This ACL has to be improved. Role member is sufficient.

- service: image
  method: POST
  path: /v2/**
- service: image
  method: GET
  path: /v2/**
- service: image
  method: PATCH
  path: /v2/**
- service: image
  method: DELETE
  path: /v2/**
- service: image
  method: PUT
  path: /v2/**