Allow manual ack and nack to take multiple messages

[ghostbuster91]

Currently messages for manual ack and nack in PersistentSubscriptionActor are defined as follows:

  final case class ManualAck(eventId: Uuid)
  final case class ManualNak(eventId: Uuid)

While the underlying api allows to pass there multiple events id:

    case Event(PSA.ManualAck(eventId), details: PSA.SubscriptionDetails) =>
      toConnection(Ack(details.subscriptionId, eventId :: Nil))
      stay
    case Event(PSA.ManualNak(eventId), details: PSA.SubscriptionDetails) =>
      toConnection(Nak(details.subscriptionId, List(eventId), Retry, None))
      stay
  }

Is there any valid reason why options to pass lists isn't exposed?