[Ongoing]-[1000USDT]-Light wallet upgrade development task

Bonus: 1000 USDT equivalent of NULS
奖金:1000 USDT等值NULS

Based on the current wallet.nuls.io, add the function of multi-sign account
Features:
Multi-sign account creation
Multi-sign account to initiate transactions: transfer, commission, cancel commission, create node, stop node, deploy contract, call contract
Multi-sign transaction signature and broadcast

在当前wallet.nuls.io的基础上,增加多签账户的功能
功能:
多签账户创建
多签账户发起交易:转账、委托、撤销委托、创建节点、停止节点、部署合约、调用合约
多签交易的签名、广播