Idea: Implement a command to let you send messages using nicknames instead of usernames

[amethyze]

Currently, every message you send either from revolt or discord, uses the username. However, I think it'd be cool if there was a way to enable nicknames instead of usernames, something like /nicks and rc!nicks. The same would work for server profile pictures, since those with nitro on discord can change their profile picture per-server, and anyone on revcord can change their profile picture as well, but the bot uses the user profile picture and not the server one.