presence: Per user allow/deny lists

Hi there.

I don't like telling everyone on all servers I'm on whether I am available, online, idle etc. So I have set my discord presence to "invisible", permanently.

Problem is, I'd quite like *some* people to see my real presence.

So how about an optional feature where you can specify a default presence, a switch for default allow or default deny, plus a list of users who are exceptions from the default.

If the feature is not enabled, presence would work exactly as it does now, with everyone seeing everyone else's real presence (or whatever they set their presence to from time to time).

If the feature is enabled, it works as follows:

- Default allow with no users in the exception list would work exactly as presence does now. Everyone would see your real presence.

- Default deny with no users in the exception list would display your default presence to everyone.

- Default allow with entries in the exception list would display your real presence to everyone except the users in the list; those users would see your default presence.

- Default deny with entries in the exception list would display your default presence to everyone except those in the exceptions list; they would see your real presence.

Regards, K.