ddoJs for v5

[AdriGeorge]

Fixes # .

Changes proposed in this PR:

• integrated policy server
• allow publish v5 with ddo.js
• download v5 with ddo.js throw command: npm run cli download did path serviceId
• start free compute for v5 with ddo.js
• start paid compute for v5 with ddo.js
• publish algo v5 with ddo.js
• allow/disallow algo v5 with ddo.js
• added metadata example for dataset and algo v5
• edit download to accept optionally serviceId
• edit startFreeCompute/startCompute to accept optionally serviceIds and algoServiceId
• README
• update tests

need to set also env for v5 like:

• export SSI_WALLET_API=""
• export SSI_WALLET_ID=""
• export SSI_WALLET_DID="" (this is optional, if not settet, will use the first one)