"Watch" functionality

[LunaUrsa]

Back on IRC there was this functionality where you could set a flag on a user and if they came online a bot would DM you "soandso has come online"

It was good to keep a watch on troublemaker users, and to set reminders for "i need to talk to this person when they're next online"

Add the ability to watch for a user, and when they say something in chat send a notification.

The command should take a few options:

target:member:required
sendMeDm:boolean:optional
alertChannel:Channel:optional

There should be checking to see if an alert is already set in the channel so that it doesn't send multiple alerts, but multiple people should be able to watch for the same user and each of them should get a DM when the user posts.

Note that we need to use the message functionality because 1) we don't even have access to the presence (online/offline) status of a user via the bot (discord rejected that) and 2) that's not even reliable anyway

Send a message to the log room: