Implement emoji encoding

[sneurlax]

Related info:

• https://github.com/search?q=repo%3AEpicCash%2Fepic-wallet%20emoji&type=code
• https://github.com/EpicCash/epic-wallet/releases/tag/v3.3.2

as well as a PDF with explanation and examples which may be found in the "Stack drops" Telegram group.