Previously, CREATE MATERIALIZED VIEW ... WITH DATA populated the MV
the same way as CREATE TABLE ... AS.
Instead, reuse the REFRESH logic, which locks down security-restricted
operations and restricts the search_path. This reduces the chance that
a subsequent refresh will fail.
Reported-by: Noah Misch
Backpatch-through: 17
Discussion: https://postgr.es/m/20240630222344.db.nmisch@google.com