pgsql: psql: Show comments in \dRp+, \dRs+, and \dX+ psql meta-commands

psql: Show comments in \dRp+, \dRs+, and \dX+ psql meta-commands.

Previously, the psql meta-commands that list publications, subscriptions,
and extended statistics did not display their associated comments,
whereas other \d meta-commands did. This made it inconvenient for users
to view these objects together with their descriptions.

This commit improves \dRp+ and \dRs+ to include comments for publications
and subscriptions. It also extends the \dX meta-command to accept the + option,
allowing comments for extended statistics to be shown when requested.

Author: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Co-authored-by: Jim Jones <jim(dot)jones(at)uni-muenster(dot)de>
Reviewed-by: Matheus Alcantara <matheusssilv97(at)gmail(dot)com>
Reviewed-by: Chao Li <li(dot)evan(dot)chao(at)gmail(dot)com>
Discussion: https://postgr.es/m/CAHGQGwGL4JqiKA26fnGx-cTM=VzoTs_uzqejvj4Fawyr4uLUUw@mail.gmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/aecc558666ad62fbecb08ff7af1394656811a581

Modified Files
--------------
doc/src/sgml/ref/psql-ref.sgml | 4 +-
src/bin/psql/command.c | 2 +-
src/bin/psql/describe.c | 40 ++-
src/bin/psql/describe.h | 2 +-
src/bin/psql/help.c | 2 +-
src/test/regress/expected/publication.out | 456 ++++++++++++++---------------
src/test/regress/expected/stats_ext.out | 60 ++--
src/test/regress/expected/subscription.out | 176 +++++------
8 files changed, 379 insertions(+), 363 deletions(-)