pgsql: Allow db.schema.table patterns, but complain about random garbag

Allow db.schema.table patterns, but complain about random garbage.

psql, pg_dump, and pg_amcheck share code to process object name
patterns like 'foo*.bar*' to match all tables with names starting in
'bar' that are in schemas starting with 'foo'. Before v14, any number
of extra name parts were silently ignored, so a command line '\d
foo.bar.baz.bletch.quux' was interpreted as '\d bletch.quux'. In v14,
as a result of commit 2c8726c4b0a496608919d1f78a5abc8c9b6e0868, we
instead treated this as a request for table quux in a schema named
'foo.bar.baz.bletch'. That caused problems for people like Justin
Pryzby who were accustomed to copying strings of the form
db.schema.table from messages generated by PostgreSQL itself and using
them as arguments to \d.

Accordingly, revise things so that if an object name pattern contains
more parts than we're expecting, we throw an error, unless there's
exactly one extra part and it matches the current database name.
That way, thisdb.myschema.mytable is accepted as meaning just
myschema.mytable, but otherdb.myschema.mytable is an error, and so
is some.random.garbage.myschema.mytable.

Mark Dilger, per report from Justin Pryzby and discussion among
various people.

Discussion: https://www.postgresql.org/message-id/20211013165426.GD27491%40telsasoft.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/d2d35479796c3510e249d6fc72adbd5df918efbf

Modified Files
--------------
doc/src/sgml/ref/psql-ref.sgml | 17 +-
src/bin/pg_amcheck/pg_amcheck.c | 27 +-
src/bin/pg_amcheck/t/002_nonesuch.pl | 99 ++++-
src/bin/pg_dump/pg_dump.c | 65 ++-
src/bin/pg_dump/pg_dumpall.c | 13 +-
src/bin/pg_dump/t/002_pg_dump.pl | 107 +++++
src/bin/psql/describe.c | 504 ++++++++++++++--------
src/fe_utils/string_utils.c | 129 ++++--
src/include/fe_utils/string_utils.h | 6 +-
src/test/regress/expected/psql.out | 804 +++++++++++++++++++++++++++++++++++
src/test/regress/sql/psql.sql | 242 +++++++++++
11 files changed, 1796 insertions(+), 217 deletions(-)