Bridge - friendly usernames across protocols

[arfonzo]

• Map Telegram usernames, i.e., @ArfonzoCoward mentioned in Discord will render as a @mention in Telegram.

• UserIDs from discord should be converted into friendly names for Telegram:

[discord] Frosty: Nice! Great job <@286217472028442624>
[discord] arfonzo: Thank you very much <@266498282241523715> , tip most appreciated 😃