Fix conflict between automatic empty thread delete & auto-warn

[FloatingMilkshake]

This PR closes #223.

If a user opens a forum thread and their original message contains content that Cliptok would issue an automatic warning for, it will delete the thread and send the warning to the configured fallback channel*. This bypasses the existing empty thread auto-delete logic, because we do not delete the message before deleting the thread—therefore we no longer have a conflict between the auto-warn and thread auto-delete logic. The infringing message is logged to the typical mod log channels when the warning is issued, so it's not a concern that the individual message isn't logged to message log channels like it would typically be when deleted.

Since this does not target any specific forum channels and instead only compares types (DiscordChannelType.GuildForum), it applies to any forum channel—#tech-support-forum, #feedback-hub-forum, etc!

*If no fallback channel is configured, Cliptok will still attempt to send into the thread, but will probably fail. It will also log a warning suggesting that you configure a fallback channel.

[Erisa]

Seems fine. Only comment is that wasAutoWarn is an odd way to pass this intent when all it does is change a 0 to a 1, maybe a minMessages param would work better that defaults to 0 annd can be changed to 1.

[FloatingMilkshake]

I considered using something like minMessages—not sure why I decided against it. So there it is :P