A question waiting for the shopper no longer reads as a system fault

A question block the shopper never answered is now read as a reply. When the assistant answered with only a question block (the assistant's questions with choices) and the shopper left without picking one, conversation labeling read that reply as empty. The conversation got the system fault flag and, when it was the only reply, the containment no_answer.

Now a question block that was shown and is waiting for the shopper counts as a reply. It no longer triggers either result. A question block that errored still counts as an error, and one cut off while it was being written still counts as empty.

This applies to conversations labeled from now on. Labels already written are not recomputed.