Update `ConditionalOverlayOwner` to reflect the fact it's no longer a client-only interface

[EnnuiL]

With that, we can actually reflect its real usage: to indicate mobs that have a charged "armor", like (charged) creepers and (armored) withers; Mojang uses PoweredMob, we could inspire ourselves from it (although powered is definitely because of "powered creepers" (their alternative and official? name), which is biased and bad)