FReplicatedPredictionKeyItem::FReplicatedPredictionKeyItem

As we know that [FReplicatedPredictionKeyItem](API\Plugins\GameplayAbilities\FReplicatedPredictionKeyItem) is well behaved and does not leak outside of [FReplicatedPredictionKeyMap](API\Plugins\GameplayAbilities\FReplicatedPredictionKeyMap) we allow ReplicationID and ReplicationKey to be copied around to avoid issues when instantiating from archetype or CDO.