Add AI factions (#1807)

* Add NPC faction tags

Some stuff isn't easy to represent by the existence of components so tags are intended to provide that functionality for AI usage.

I was 50/50 on having all tags in the 1 component or splitting it into 2. I'm leaning towards 2. This would be for stuff like say "CanMimic" so the mimic knows it's allowed to look like a specific prototype, or something like "smg" on a gun so it can say smg-specific barks for instance (as currently smgs and pistols look the same from a component perspective).

This also means combat behaviors aren't hardcoded per faction, plus it makes it easy to update faction relations during events.

* Factions command

Update faction relationships via commands.

* Remove command TODO

* Woops

Forgot to commit these items

* Serializer writing and parsing

* linq me up fam

Co-authored-by: Metal Gear Sloth <metalgearsloth@gmail.com>

Content.Server/AI/Utility/BehaviorSets/SpirateBehaviorSet.cs

@@ -14,7 +14,7 @@ namespace Content.Server.AI.Utility.BehaviorSets
                 // TODO: Ideally long-term we should just store the weapons in backpack
                 new EquipMeleeExp(),
                 new PickUpMeleeWeaponExp(),
-                new MeleeAttackNearbyPlayerExp(),
+                new MeleeAttackNearbyExp(),
             };
         }
     }