[feat] CORS Configuration

[St4NNi]

Problem

Updated version for V2

Integrating Aruna URL / S3 links into other websites is currently not possible because appropriate user-configurable CORS http headers are missing. Amazon S3 allows users to configure these per bucket via the PutBucketCors requests.

Aruna should allow users to use this API, internally this would add CORS configuration labels to each collection. This way it would also be possible to configure CORS at ArunaAPI level.

Todo

• Wait for the upstream lib to allow for response header modifications (Response HTTP Headers / CORS s3s-project/s3s#43).
• Re-implement PutBucketCORS request, add CORS config as labels to project
• Add configured CORS header to object responses

[St4NNi]

Fixed by #58