pgsql: Add --disable-page-skipping and --skip-locked to vacuumdb

Add --disable-page-skipping and --skip-locked to vacuumdb

DISABLE_PAGE_SKIPPING is available since v9.6, and SKIP_LOCKED since
v12.  They lacked equivalents for vacuumdb, so this closes the gap.

Author: Nathan Bossart
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/FFE5373C-E26A-495B-B5C8-911EC4A41C5E@amazon.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/354e95d1f2122d20c1c5895eb3973cfb0e8d0cc2

Modified Files
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doc/src/sgml/ref/vacuumdb.sgml    | 32 +++++++++++++++
src/bin/scripts/t/100_vacuumdb.pl | 17 +++++++-
src/bin/scripts/vacuumdb.c        | 84 ++++++++++++++++++++++++++++++++++++---
3 files changed, 126 insertions(+), 7 deletions(-)