Correct ObjectProperty entry for transforms

Correct ObjectProperty entry for transforms

There was some confusion in the ObjectProperty entry for transforms.
Some fields had values that were apparently meant for a different
field.  Also, some fields were not assigned, which is okay for most
fields, but not for all.  In particular, for .oid_catcache_id,
.name_catcache_id, and .objtype, zero is a valid value, so we need to
use -1 if not applicable.  It has apparently been like that from the
very beginning (commit cac7658205).  The faulty values were not
actually reachable, so it's not a big problem in practice, but we
should make it correct.

Discussion: https://www.postgresql.org/message-id/flat/75ae5875-3abc-dafc-8aec-73247ed41cde@eisentraut.org