Add existing NPC names into a list not to be reused.

The names Ava, Ryker, Cerys, Maya, Aurora, Grimgar and Grimner come up a lot in my fantasy settings. I’ve had multiple copies of each with slight deviations, and although its easily resolved (and leads to some hilarious returns of dead enemies), it might be best if common names are either reduced for reuse or added to a list as the AI creates them to not pull the same name again so often.