pgsql: Add --schema and --exclude-schema options to vacuumdb.

Add --schema and --exclude-schema options to vacuumdb.

These two new options can be used to either process all tables in
specific schemas or to skip processing all tables in specific
schemas.  This change also refactors the handling of invalid
combinations of command-line options to a new helper function.

Author: Gilles Darold
Reviewed-by: Justin Pryzby, Nathan Bossart and Michael Paquier.
Discussion: https://postgr.es/m/929fbf3c-24b8-d454-811f-1d5898ab3e91%40migops.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/7781f4e3e711ace6bcf9b6253a104b180cb78fcf

Modified Files
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doc/src/sgml/ref/vacuumdb.sgml    |  66 +++++++++++++++
src/bin/scripts/t/100_vacuumdb.pl |  42 ++++++++++
src/bin/scripts/vacuumdb.c        | 172 +++++++++++++++++++++++++++++---------
3 files changed, 239 insertions(+), 41 deletions(-)