Fix gas estimate and command issues

[Jason-W123]

Description

Because in rust ethers, the eip1559_default_estimator will set a high base_fee_per_gas and priority_fee to EIP1559_FEE_ESTIMATION_DEFAULT_PRIORITY_FEE (3_000_000_000) if network fee lower than this default value (EIP1559_FEE_ESTIMATION_PRIORITY_FEE_TRIGGER , 100_000_000_000), however, on arbitrum, the network fee is significant lower than this. And if the cli tool use this default fee to send tx which will cause the tx body's gas fee set super higher than what it actually needs and might lead to tx failed if users don't have that much balance in wallet.

Also, for --max-fee-per-gas-gwei config, it uses u128, however, user might input like 0.02 value, so we need to reset it to string and use a method to convert it.