pgsql: Simplify options in pg_dump and pg_restore.

Simplify options in pg_dump and pg_restore.

Remove redundant options --with-data and --with-schema, and rename
--with-statistics to just --statistics.

Reviewed-by: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Reviewed-by: Fujii Masao <masao(dot)fujii(at)gmail(dot)com>
Discussion: https://postgr.es/m/f379d0aeefe8effe13302a436bc28f549f09e924.camel@j-davis.com
Backpatch-through: 18

Branch
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REL_18_STABLE

Details
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https://git.postgresql.org/pg/commitdiff/a3e8dc14386221e2db0fe92589327c5b2dea22af

Modified Files
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doc/src/sgml/ref/pg_dump.sgml | 38 ++++--------
doc/src/sgml/ref/pg_dumpall.sgml | 38 ++++--------
doc/src/sgml/ref/pg_restore.sgml | 40 ++++---------
src/bin/pg_dump/pg_dump.c | 43 ++++----------
src/bin/pg_dump/pg_dumpall.c | 16 +----
src/bin/pg_dump/pg_restore.c | 35 ++++-------
src/bin/pg_dump/t/002_pg_dump.pl | 124 +++++++++++++++++++--------------------
src/bin/pg_upgrade/dump.c | 2 +-
8 files changed, 118 insertions(+), 218 deletions(-)