Name: auth-service-definition
Type: request
Purpose: >
  Defines ("creates") a new authentication service
Response: auth-service-details
Inherits: message
Elements:
  Signature: { required: true }
  From: { required: true }
  Auth-Service-Data: { required: true, type: object, class: auth_service }
Rejection-Codes:
  21: Missing attributes
  22: Invalid authentication type
  23: Missing OIDC host
  24: Invalid OIDC host
  31: Sender is not authorized to define authentication services
  41: Authentication service is already defined for this target