[EPIC] Credentials support in asset

[alexcos20]

In order to support credentials based access, we are going to add the following attribute to DDO (as a root object)

 "credentials":{
      "allow":[
         {
            "type":"address",
            "values":[
               "0x123",
               "0x456"
            ]
         }
      ]
   },
   "deny":[
      {
         "type":"address",
         "values":[
            "0x2222",
            "0x333"
         ]
      }
   ]
}

where:

• "allow" - will control who can consume this asset. If array it's empty, means anyone can consume
  • "deny" - if there is a match, consumption is denied

For future usage, we can extend that with different credentials types. Example:

         {
            "type":"credential3Box",
            "values":[
               "profile1",
               "profile2"
            ]
         }

All conditions are OR based

Action list:

• [X] update OEP
• [x] update ocean.js
• [x] update ocean.py
• [x] update provider
• [x] Update market

[alexcos20]

OEP already updated in https://github.com/oceanprotocol/OEPs/tree/master/7/v0.3#credentials

[alexcos20]

this is done, we can close it