Align DDO structure with industry standards (W3C VC) - stack update

[MBadea17]

Feature # 95.2

[alexcos20]

Since now we have the structure for the new DDO, it's time to implement it.

TO DO:

• decide what DID_METHOD to use (did:op (status quo) or did:ope)

If we decide did:op , let's have another version (call it 5.0.0)

• create shacl schema file (5.0.0.ttl) for validation in schema folders. (see https://github.com/oceanprotocol/ocean-node/tree/develop/schemas)
  A good example is https://github.com/oceanprotocol/ocean-node/blob/develop/schemas/4.5.0.ttl

If we decide did:ope , the task is much bigger

• change the code to validate DIDs using only identifier part, and not hardcode DID_METHODx (ocean-node is using hardcoded did:op pretty much everywhere)
• change schema folder to use DID_METHOD-DID_VERSION.ttl files
• change ocean-node to load the ttl file based on both DID_METHOD and DID_VERSION (now it's loading based only on version)
  All code is located in https://github.com/oceanprotocol/ocean-node/blob/develop/src/components/core/utils/validateDdoHandler.ts

[MBadea17]

As agreed in the weekly meeting on July 23rd, we will implement the did:ope method.