[security feature] ERC20 Transaction: Data decode

[recolic]

offline signer should be able to decode ERC20 data for common transactions "such as USDC/USDT token transfer, token approval, change authorization limit, DEFI trade, ..."

Otherwise we are just doing blind signing without knowing what the data means. It's a significant security concern unless relying some external ETH transaction decoder.

Possible impl

we can have a separate module "erc_data_decoder.ts" and add common data parser as needed. Just cover the most widely-used contract and community will keep adding more.

[recolic]

POC code for USDT/USDC transfer/approval decode:
https://github.com/recolic/daily-scripts/blob/9aa74e088a5f1e17dd2e428e4808cc47d8e2a421/docker-keystone-qr-parser/main.py#L7