Implement access control config client to setup default permissions in `petstore`

This issue is blocked by #146.
Once the client is implemented, we need to use that client in the `petstore` example to automatically set the permissions of a newly created resource such that the creator becomes the owner of the resource, i.e., they should be allowed to read (GET /petsandGET /pets/{id}) and delete (DELETE /pets/{id}`) the resource. 