pgsql: Skip .DS_Store files in server side utils

Skip .DS_Store files in server side utils

The macOS Finder application creates .DS_Store files in directories
when opened,  which creates problems for serverside utilities which
expect all files to be PostgreSQL specific files.  Skip these files
when encountered in pg_checksums, pg_rewind and pg_basebackup.

This was extracted from a larger patchset for skipping hidden files
and system files, where the concencus was to just skip these. Since
this is equally likely to happen in every version, backpatch to all
supported versions.

Reported-by: Mark Guertin <markguertin@gmail.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Tobias Bussmann <t.bussmann@gmx.net>
Discussion: https://postgr.es/m/E258CE50-AB0E-455D-8AAD-BB4FE8F882FB@gmail.com
Backpatch-through: v12

Branch
------
REL_15_STABLE

Details
-------
https://git.postgresql.org/pg/commitdiff/29f00523808ac1d646cf51f9fe199e61ce5631e7

Modified Files
--------------
doc/src/sgml/protocol.sgml                   |  2 +-
doc/src/sgml/ref/pg_basebackup.sgml          |  3 ++-
doc/src/sgml/ref/pg_rewind.sgml              |  5 +++--
src/backend/backup/basebackup.c              |  4 ++++
src/bin/pg_basebackup/t/010_pg_basebackup.pl | 17 +++++++++++++++++
src/bin/pg_checksums/pg_checksums.c          |  4 ++++
src/bin/pg_checksums/t/002_actions.pl        |  7 +++++++
src/bin/pg_rewind/filemap.c                  |  4 ++++
src/bin/pg_rewind/t/003_extrafiles.pl        |  5 +++++
9 files changed, 47 insertions(+), 4 deletions(-)