Public data service

[alexcos20]

For publicly available datasets, it does make sense to reduce consume friction, by not encrypting the url and allow consumers to bypass smartcontracts/provider, although this completely removes traceability & provenance.

Proposal: Add a new key to service object, called "publicData". This will contain an array of files object (see https://docs.oceanprotocol.com/core-concepts/did-ddo#files). In a nutshell, this is equivalent with original files object before being encrypted by the provider in the current setup

Service example:

{
  "services": [
    {
      "id": "1",
      "type": "publicData",
      "files": [{
                   "type": "url",
                   "url": "https://url.com/file1.csv",
                   "method": "GET",
                   "headers":
                           [
                              {"Authorization": "Bearer 123"}, 
                              {"APIKEY": "124"},
                   ]
      }],
      "name": "Download service",
      "description": "Download service",
    },

To Do:

• [ ] Update Aquarius shacl schema
• [ ] Ocean.js can publish public data assets
• [ ] Ocean.py can publish public data assets
• [ ] Ocean.js can download public data assets without provider
• [ ] Ocean.py can download public data assets without provider
• [ ] Provider can download public data assets (used for C2d compatibility)
• [ ]