NeverSavedWithChunkEntity
Decorator for entities that will never be saved with a chunk. Entities implementing this interface are not required to register a save ID.
This differs from Entity::canSaveWithChunk() because it can't be changed after the entity is created. We can't use canSaveWithChunk() to decide whether an entity needs a save ID, but we can use an interface like this. An attribute would also work, but instanceof NonSaveable is easier.
