Better error message for unsupported replication cases

In [1] there's a complaint that if you try to logically replicate
a partitioned table from v13-or-later to v12-or-earlier, you get
"table XXX not found on publisher", which is pretty confusing
because the publisher certainly does have such a table.  That
happens because fetch_remote_table_info is too aggressive about
filtering by relkind and doesn't see the relation at all.
c314c147c improved that, but it wasn't back-patched.  I propose
putting the attached into v10-v12.  Maybe the error message
could be bikeshedded ... is "non-table relation" terminology
that we use in user-facing messages?

			regards, tom lane

[1] https://www.postgresql.org/message-id/CANhtRiamAgYt1A-Nh4%3DmU3E1UhG9XPgB%2BX6mW1DWqa93vUXW9A%40mail.gmail.com