Storing and retrieving blobs

As a logistics user, I'd like to be able to store binary objects (blobs) in a blob storage and attach them to a logistics object via link.

Acceptance criteria

• Blob storage set up as a container. The chosen product should ideally use a common API (e.g. Amazon S3 compatible) so that it can be exchanged against other user-selected storages.
• A NE:ONE API abstracts the blob storage API:
  • It allows to request the blob object under the given link
  • It applies the ACLs for the parent object (ExternalReference) to the blob object itself. Thus, a user must have read access to the parent object according to the ACL in order to request the blob object via the API.