port Darrik's emoji reaction code to rust bot

[ChristopherBiscardi]

Darrik wrote some code that I can no longer find :sigh: to remove the ok hand reaction from posts and inform the user via DM why it was removed. We should port that code to the rust bot.

[mdarrik]

I've got the JS code here if someone wants to look at it. Not 100% sure how it transfers over to serenity tbh, but the approach is probably solid.

https://github.com/mdarrik/party-corgi/blob/mdarrik/create-corgi-bot/packages/corgi-bot/index.js#L14

[mdarrik]

It does look like serenity has a built-in emoji parser, which might be useful? I don't know if it handles unicode emojis or not though. Definitely worth looking into for whoever handles this.

https://docs.rs/serenity/0.8.7/serenity/utils/fn.parse_emoji.html