pgsql: Fix a WARNING for data origin discrepancies.

Fix a WARNING for data origin discrepancies.

Previously, a WARNING was issued at the time of defining a subscription
with origin=NONE only when the publisher subscribed to the same table from
other publishers, indicating potential data origination from different
origins. However, the publisher can subscribe to the partition ancestors
or partition children of the table from other publishers, which could also
result in mixed-origin data inclusion. So, give a WARNING in those cases
as well.

Reported-by: Sergey Tatarintsev <s(dot)tatarintsev(at)postgrespro(dot)ru>
Author: Hou Zhijie <houzj(dot)fnst(at)fujitsu(dot)com>
Author: Shlok Kyal <shlok(dot)kyal(dot)oss(at)gmail(dot)com>
Reviewed-by: Vignesh C <vignesh21(at)gmail(dot)com>
Reviewed-by: Amit Kapila <amit(dot)kapila16(at)gmail(dot)com>
Backpatch-through: 16, where it was introduced
Discussion: https://postgr.es/m/5eda6a9c-63cf-404d-8a49-8dcb116a29f3@postgrespro.ru

Branch
------
REL_16_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/1c2a2354c3848d9f03dc627270bdca073a5a37bc

Modified Files
--------------
doc/src/sgml/ref/create_subscription.sgml | 12 +--
src/backend/commands/subscriptioncmds.c | 15 ++--
src/test/subscription/t/030_origin.pl | 120 +++++++++++++++++++++++++++++-
3 files changed, 133 insertions(+), 14 deletions(-)