pgsql: Throw a more on-point error for publications depending on column

Throw a more on-point error for publications depending on columns.

Same as 42b041243, except that the trouble case is a publication
WHERE clause that depends on a column.

Again reported by Alexander Lakhin.  Back-patch to v15 where
we added publication WHERE clauses.

Discussion: https://postgr.es/m/548a47bc-87ae-b3df-c6a2-60b9966f808b@gmail.com

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/5f4a1a0a7758bb3bd0cfa58a48a1537bb2c0024b

Modified Files
--------------
src/backend/commands/tablecmds.c | 15 ++++++++++++++-
1 file changed, 14 insertions(+), 1 deletion(-)