More polished combat – spawn points, hit reactions, and dying

So now we have an AI that likes to chase down our player and try to hurt them, great. But at this stage, our player can do almost no interaction with that enemy. We'll want to make things a bit more professional by spawning the enemies from a spawn point actor rather than placing them directly in the level (so we can spawn multiple enemies, wait until they are triggered, and so on), have them react when they're shot (which should not interrupt their other activities, but simply layer on top of them with a blended animation), and of course, be able to kill them (and have all of this reflected when loading/saving).