[64] Vendor agnostic S3 implementation

[alexcos20]

Current status:

• ocean-node has no S3 access implementation
• c2d v2 will use ocean-node

We need a solution that is vendor agnostic, meaning it will work with other implementations of S3 (see https://www.coralnodes.com/amazon-s3-alternatives/, https://docs.ceph.com/en/latest/radosgw/s3/, https://min.io/product/s3-compatibility)

To do:

• [ ] research available libraries
• [ ] define how files structure will look like (see https://docs.oceanprotocol.com/developers/storage)
• [ ] update ocean-node with S3 Storage class to allow read/write