PendingReceivedMessagePage

One page of SecureMessageClient.pendingReceivedMessages (docs/message-discard.md): messages in ascending ReceivedMessage.sequence order.

nextAfterSequence is the sequence of the last message if more pending messages existed when the page was read; pass it as afterSequence for the next page. null means the enumeration reached the end; messages accepted later have higher sequence numbers, so to see them, continue after the last sequence you received.