Log kick events into the private moderation log

[danirod]

If a moderator kicks an user, Clank should send a ModlogEvent into the private modlog channel indicating that the user has been kicked from the server. Additionally, if the mod provided a reason to Discord when issuing the kick, the reason should be logged in the message as well.

The reason is that, seeing why a user was kicked is difficult because it requires opening the audit log in the server settings, plus it is difficult by itself because you might not know that an user was kicked unless you actually reviewed the audit log itself.

[danirod]

Discord does not emit into the API an event whenever a user is kicked, so I don't have a way to do this.