Create a delegate signature for Annex Governance using EIP-712. The signature can be created without burning gas. Anyone can post it to the blockchain using the delegateBySig method, which does have gas costs.
delegatee (string) The address to delegate the user's voting rights to.
[expiry] (number) The time at which to expire the signature. A block timestamp as seconds since the unix epoch. Defaults to 10e9.
RETURN (object) Returns an object that contains the v, r, and s components of an Ethereum signature as hexadecimal strings.