Protect RPCs with 2FA

[altafan]

Let's add a password_hash string field to Transfer request message in order to protect this endpoint in such a sensitive operation.

[tiero]

For Ocean instead it may be interesting to move to 2fa/topt server as definitive solution.

Also some user may and other may not want it, so it should be enabled at will and maybe for all and specific RPCs

[altafan]

Not sure if requiring 2fa for generating a receiving address is a feature from user POV.

Tipically, wallets protect with 2fa the login, the transfer of funds and eventually some settings operation like changing the password for example. We could start by protecting these 3 RPCs initally.

[tiero]

Yes agreed, but my point was that if we have a whitelist/blacklist system to filter out RPCs would be easier to add/remove the protected route at will