For PostgreSQL::Test compatibility, alias entire package symbol tables.

For PostgreSQL::Test compatibility, alias entire package symbol tables.

Remove the need to edit back-branch-specific code sites when
back-patching the addition of a PostgreSQL::Test::Utils symbol.  Replace
per-symbol, incomplete alias lists.  Give old and new package names the
same EXPORT and EXPORT_OK semantics.  Back-patch to v10 (all supported
versions).

Reviewed by Andrew Dunstan.

Discussion: https://postgr.es/m/20220622072144[email protected]