Signature refactor

[alexcos20]

In our backends, we are using the following logic to sign requests:

web3.eth.sign(encode_defunct(message), wallet)  (py)
web3.eth.sign(message, wallet)   (js)

which is incompatible with how signatures are checked in solidity

Proposal:

• generate the hash first, by converting message to bytes and using keccak
  • sign the hash

ie:

consumerMessage = web3.utils.soliditySha3({
      t: 'bytes',
      v: web3.utils.utf8ToHex(message)
 })
consumerSignature = web3.eth.sign(consumerMessage, wallet)

This requires a refactor on multiple components, and thus they need to be merged/deployed in the same time.

Affected repos:

• aquarius
• provider
• ocean.js
• ocean.py
• operator-service
• pod-configuration