psql: Add command to use extended query protocol

When Who What
2022-11-15 13:33:36 Peter Eisentraut (petere) Closed in commitfest 2022-11 with status: Committed
2022-11-15 13:33:36 Peter Eisentraut (petere) Changed committer to petere
2022-11-15 13:33:31 Peter Eisentraut (petere) Changed reviewers to Corey Huinker (coreyh)
2022-10-29 08:34:37 Peter Eisentraut (petere) Changed authors to Peter Eisentraut (petere)
2022-10-29 08:34:31 Peter Eisentraut (petere) Attached mail thread e8dd1cd5-0e04-3598-0518-a605159fe314@enterprisedb.com
2022-10-29 08:34:31 Peter Eisentraut (petere) Created patch record