Optimize the Buffer, check and modify the following codes

[limsbase]

• Buffer.from(transfer.amount, 'utf8') : if transfer.amount is not string, it will throw an error.
• Buffer.from([asset.precision || 0]): Can it be optimized？
• Buffer.from(asset.currency, 'utf8') : Encoding default is utf8, instead of Buffer.from(asset.currency, 'hex')?
  ...

[limsbase]

https://nodejs.org/dist/latest-v12.x/docs/api/buffer.html#buffer_buffers_and_character_encodings