pgsql: Ignore dropped columns during apply of update/delete.

Ignore dropped columns during apply of update/delete.

We fail to apply updates and deletes when the REPLICA IDENTITY FULL is
used for the table having dropped columns. We didn't use to ignore dropped
columns while doing tuple comparison among the tuples from the publisher
and subscriber during apply of updates and deletes.

Author: Onder Kalaci, Shi yu
Reviewed-by: Amit Kapila
Discussion: https://postgr.es/m/CACawEhVQC9WoofunvXg12aXtbqKnEgWxoRx3+v8q32AWYsdpGg@mail.gmail.com

Branch
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REL_12_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/fc63e6ba8670e0eb1bc40ae9fe4acdd4203bc36e

Modified Files
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src/backend/executor/execReplication.c | 10 ++++--
src/test/subscription/t/100_bugs.pl    | 57 +++++++++++++++++++++++++++++++++-
2 files changed, 64 insertions(+), 3 deletions(-)