Command: encrypt - Add user signature

[alexcos20]

Now, the encrypt command can be called by anyone, without any type of auth.
This can lead to some DDOS attacks.
So, let's add auth on this command

Modules to update:

Commands:

• add consumerAddress & signature required parameters
• check signature when somebody is trying to use this handler
• add optional policyServer input param, which gets sent to policyServer

Http:

• update http route

PolicyServer:

• add policyServer command, so an owner can decide who can have access ( { action: 'encrypt',
  consumerAddress,
  policyServer
  }

##Warning:

• this has breaking changes for ocean.js/cli, so they need to be updated