Add ENS support for Moderator

[shayanb]

• Use ENS auctionify.eth for the moderator.
• Set resolver for .eth domain to the moderator address
• Get moderator .eth domain as an input

[shayanb]

    function namehash(bytes32 name) public pure returns (bytes32 result) {
        // 
        assembly {
             mstore(0, 0)

             if iszero(byte(0, name)) {
                 return(0, 32)
             }

             let scratch := mload(0x40)
             mstore8(add(scratch, 1), 0x2e)
             mstore(add(scratch, 2), name)

             // Find the end of the null-terminated bstring
             let back := add(scratch, 33)
             let front := sub(back, 1)
             for { } gt(front, scratch) { } {
                 switch byte(0, mload(front))
                     case 0x00 {
                         back := front
                     }
                     case 0x2e {
                         mstore(32, sha3(add(front, 1), sub(sub(back, front), 1)))
                         mstore(0, sha3(0, 64))
                         back := front
                     }
                 front := sub(front, 1)
             }

             //return(0, 32)
             result := mload(0)
        }
}



        bytes32 nodehash = namehash(ensName);
        AbstractPublicResolver resolver = _ens.resolver(nodehash);
        address addr = resolver.addr(nodehash);
        require(addr != address(0), "ENS name resolved to null addr");

Ref: https://ropsten.etherscan.io/address/0x199862247977a88aD825e8d4652a9d7a6EF0f40d#code