pgsql: Rework options of pg_checksums options for filenode handling

Rework options of pg_checksums options for filenode handling

This makes the tool consistent with the option set of oid2name, which
has been historically using -f for filenodes, and has more recently
gained long options and --filenode via 1aaf532.

Reported-by: Peter Eisentraut
Author: Fabien Coelho
Discussion: https://postgr.es/m/97045260-fb9e-e145-a950-cf7d28c4eaea@2ndquadrant.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/fc115d0f9fc656967260815c031e0f25741428ae

Modified Files
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doc/src/sgml/ref/pg_checksums.sgml    | 34 +++++++++++-----------
src/bin/pg_checksums/pg_checksums.c   | 53 ++++++++++++++++++-----------------
src/bin/pg_checksums/t/002_actions.pl |  8 +++---
3 files changed, 49 insertions(+), 46 deletions(-)