pgsql: Standardize use of REFRESH PUBLICATION in code and messages.

Standardize use of REFRESH PUBLICATION in code and messages.

This patch replaces ALTER SUBSCRIPTION REFRESH with
ALTER SUBSCRIPTION REFRESH PUBLICATION in comments and error messages to
improve clarity and support future extensibility. The change aligns with
upcoming addition REFRESH SEQUENCES for sequence synchronization.

Author: vignesh C <vignesh21@gmail.com>
Author: Hou Zhijie <houzj.fnst@fujitsu.com>
Reviewed-by: shveta malik <shveta.malik@gmail.com>
Reviewed-by: Dilip Kumar <dilipbalaut@gmail.com>
Reviewed-by: Peter Smith <smithpb2250@gmail.com>
Reviewed-by: Hayato Kuroda <kuroda.hayato@fujitsu.com>
Reviewed-by: Amit Kapila <amit.kapila16@gmail.com>
Discussion: https://postgr.es/m/CAA4eK1LC+KJiAkSrpE_NwvNdidw9F2os7GERUeSxSKv71gXysQ@mail.gmail.com

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/2436b8c047fff793c9d115dd0acb48c0b6e114d9

Modified Files
--------------
src/backend/commands/subscriptioncmds.c      | 51 ++++++++++++++--------------
src/backend/parser/gram.y                    |  2 +-
src/include/nodes/parsenodes.h               |  2 +-
src/test/regress/expected/object_address.out |  2 +-
src/test/regress/expected/subscription.out   | 28 +++++++--------
5 files changed, 43 insertions(+), 42 deletions(-)