feat: command to cure usernames

## 🐞 Issue

If a user joins during bot downtime or the bot cure bugs out, the only way to cure the username is by adding and removing a role.

## ❗ Solution

Could you create a command to run the cure method on a user on demand?

## ❓ Motivation

The original method of curing those cases is annoying.

## ⚠ Additional context

None.
