[proton-j] stale entries can stick in transport work list upon freeing session with outstanding deliveries

In certain circumstances it is possible for delivery entries to make it into the transport work list which then cant be actioned, but are not cleared as they weren't actioned, meaning the list retains the delivery, link, and session. This was noticed after freeing a closed session without previously closing a link that still had outstanding delivery entries. Repeating this situation with lots of sessions on a long lived connections can lead to significant retention. The transport should clear such cases from the work list if encountered, and we should prevent their creation where possible.