Feature request: Allow FredBoat to DM me track announcements

[fishstik]

Many times server admins turn off now playing announcements with track_announce = false. For those times, I would like to have FredBoat announce new tracks as a DM to me. I imagine it could be implemented by sending a command in the server channel (e.g. ;;dmnowplaying) to 'subscribe' to DM announcements. Then something like ;;stopdm (either in the server channel or via DM) to stop the announcements.

Would this be feasible?

[freyacodes]

Discord has somewhat strict limitations on DMs, so this would probably not be useful on the large public FredBoat instance.

We also don't have a way to store per-user preferences, so that's a bit tricky.