pgsql: Message style improvements

Message style improvements

Some message style improvements in new code, and some small
refactorings to make translations easier.

Branch
------
master

Details
-------
https://git.postgresql.org/pg/commitdiff/a876464abc73eccc04543da6a12eb5b1ffcd6dfd

Modified Files
--------------
src/bin/pg_basebackup/pg_createsubscriber.c | 12 +++---
src/bin/pg_basebackup/pg_recvlogical.c | 2 +-
src/bin/pg_basebackup/t/040_pg_createsubscriber.pl | 4 +-
src/bin/pg_dump/pg_dump.c | 8 ++--
src/bin/pg_dump/pg_dumpall.c | 8 ++--
src/bin/pg_dump/pg_restore.c | 43 +++++++++++++---------
src/bin/pg_dump/t/001_basic.pl | 4 +-
src/bin/pg_dump/t/006_pg_dumpall.pl | 2 +-
src/bin/pg_upgrade/check.c | 4 +-
src/bin/pg_upgrade/relfilenumber.c | 12 +++---
src/bin/pg_upgrade/t/005_char_signedness.pl | 2 +-
src/bin/pg_upgrade/task.c | 5 +--
src/bin/psql/command.c | 6 +--
src/bin/psql/describe.c | 5 ++-
src/bin/psql/help.c | 6 +--
src/bin/psql/variables.c | 10 ++---
16 files changed, 70 insertions(+), 63 deletions(-)