List messages in an inbox, newest first

Requires a full key or an inbox key (bound inbox only). A missing, deleted, other-tenant or other-mode inbox is not found. Deleted and expired messages are omitted. thread_id limits the page to one thread. Messages and list cursors are ordered by received_at and id, newest first. received_at is the original mail receive time, not the time storage completes. A late retried delivery can arrive after a newer message while retaining an earlier received_at. A cursor can therefore miss a message inserted behind its position. To reconcile retained messages, restart the list without a cursor and deduplicate by message id.