pgsql: Introduce long options in pg_archivecleanup

Introduce long options in pg_archivecleanup

This patch is a preliminary refactoring for an upcoming patch aimed at
adding new options to this tool, and using long options for these is
more user-friendly. The existing short options gain long flavors, as
of:
* -d/--debug
* -n/--dry-run
* -x/--strip-extension

Author: Atsushi Torikoshi
Reviewed-by: Fujii Masao, Kyotaro Horiguchi, Michael Paquier
Discussion: /messages/by-id/d660ef741ce3d82f3b4283f1cafd576c@oss.nttdata.com

Branch
------
master

Details
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https://git.postgresql.org/pg/commitdiff/dd7c60f1935ad3354bc77de09431313d7b0719ef

Modified Files
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doc/src/sgml/ref/pgarchivecleanup.sgml | 5 ++++-
src/bin/pg_archivecleanup/pg_archivecleanup.c | 22 +++++++++++++++-------
2 files changed, 19 insertions(+), 8 deletions(-)