refactor: replace models/keys with lumos hd

[twhy]

@ckb-lumos/hd requires HexString for PublicKey, Privatekey, ChainCode, otherwise an error is thrown.

function assertHexString(debugPath: string, str: string): void {
  if (!/^0x([0-9a-fA-F][0-9a-fA-F])*$/.test(str)) {
    throw new Error(`${debugPath} must be a hex string!`);
  }
}

[homura]

I found several instances of 0x${...} in this PR. We should avoid mixing HexString and HexStringWithout0x in one project, as this can lead to unpredictable behavior