Make Scourge invasion elites tagable to unlock stuff pls

[Lionheart-arugal]

@Lionheart-arugal

• Heart of Doom for Shoulder Enchants Unlock is now an interactible item that drops when clearing a Necrotic Shard. No longer need to tag the Shadow of Dooms.
• There seems to be only a 5 minute CD between Invasion Events in each zone.

The issues are fixed. Go get your shoulder enchants!