pgsql: Add pg_get_acl() to get the ACL for a database object

Add pg_get_acl() to get the ACL for a database object

This function returns the ACL for a database object, specified by
catalog OID and object OID. This is useful to be able to
retrieve the ACL associated to an object specified with a
(class_id,objid) couple, similarly to the other functions for object
identification, when joined with pg_depend or pg_shdepend.

Original idea by Álvaro Herrera.

Bump catalog version.

Author: Joel Jacobson
Reviewed-by: Isaac Morland, Michael Paquier, Ranier Vilela
Discussion: https://postgr.es/m/80b16434-b9b1-4c3d-8f28-569f21c2c102@app.fastmail.com

Branch
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master

Details
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https://git.postgresql.org/pg/commitdiff/4564f1cebd437d93590027c9ff46ef60bc3286ae

Modified Files
--------------
doc/src/sgml/func.sgml | 41 +++++++++++++++++++++++++++
src/backend/catalog/objectaddress.c | 48 ++++++++++++++++++++++++++++++++
src/include/catalog/catversion.h | 2 +-
src/include/catalog/pg_proc.dat | 5 ++++
src/test/regress/expected/privileges.out | 29 +++++++++++++++++++
src/test/regress/sql/privileges.sql | 6 ++++
6 files changed, 130 insertions(+), 1 deletion(-)