pgsql: Reject COPY TO of unlogged tables during recovery.

Reject COPY TO of unlogged tables during recovery.

Unlogged tables have no data on a standby, so reading one there must
fail. SELECT and COPY (SELECT ...) TO already report a clear error,
but COPY with a table name read the table directly and failed with a
low-level error instead:

ERROR: could not open file "base/5/16384": No such file or directory

Check for this case in COPY TO and report the same error as SELECT. On
v19 and later, also check each partition when copying from a
partitioned table, so that an unlogged partition is reported too.

Backpatch to all supported versions, since the low-level error looks
like data corruption.

Author: Jim Jones <jim(dot)jones(at)uni-muenster(dot)de>
Reviewed-by: Zsolt Parragi <zsolt(dot)parragi(at)percona(dot)com>
Reviewed-by: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
Discussion: https://postgr.es/m/b6d71815-d362-4579-bf07-73eca01aee6d@uni-muenster.de
Backpatch-through: 14

Branch
------
REL_19_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/2f79b0179437bd18c2aaa550f71c80e477fcc0a7

Modified Files
--------------
src/backend/commands/copyto.c | 19 +++++++++++++++++++
src/test/recovery/t/001_stream_rep.pl | 27 +++++++++++++++++++++++++++
2 files changed, 46 insertions(+)