[Feature] support displaying payment for QR code

[levisyin]

Summary

Extending account command to support displaying payment for QR code for a given index of the account in terminal, so that we can pay to this account conveniently using wallet app that supporting transfer by QR code scan.

Proposed Feature

for example: forc-wallet account 0 public-key --qrcode or forc-wallet account 0 public-key --unverified --qrcode , and then will show the payment QR code in terminal as