Restore tests (verify)

A backup that has never been restored is not a backup. Verify restores the newest backup into a scratch database, runs checks, writes the result to history and drops the scratch database. Failures alert.

SELECT pgbx.verify_now();                                   -- job id
SELECT pgbx.set_verify_schedule('weekly on sunday at 04:00'); -- the default
SELECT pgbx.set_verify_schedule('never');                   -- disable
SELECT last_verified_at, last_verify_result FROM pgbx.status();

pgbx verify --db myapp --wait
pgbx verify-schedule 'daily at 05:00' --db myapp
pgbx verify-schedule never --db myapp --yes     # guarded