AS a server moderator, I want a hackban command to let me ban users by user id, even when they're not in the server

[Vylpes]

SO THAT I can keep known troublesome users banned or ban users who left before I could ban

Acceptance Criteria

AS a server moderator GIVEN I want to ban a user not currently in the server WHEN I run /hackban <userid> [reason] THEN I the user with id <userid> will be banned with the optional reason [reason]

Subtasks

• [ ] Create hackban command
• [ ] Update tests