New rule for enlisting into the global leaderboards

An account now enlists into the global leaderboards only once we've confirmed it's playable - which sweeps banned accounts off the board.

Until now, an account showed up on the leaderboards the moment we first saw it. Now it enlists only once we've confirmed it's being played - that is, we've seen the hunter get a kill or die in a match while we're tracking them.

Until that happens the account stays off the board, but nothing is hidden: its dossier and all of its stats are there, and search still finds it. Such a dossier carries a small note explaining that the account is just being confirmed as active before it gets ranked.