Fix ordering of GRANT commands in pg_dumpall for database creation

This uses a method similar to 68a7c24f, which guarantees that GRANT
commands using the WITH GRANT OPTION are dumped in a way so as cascading
dependencies are respected.  As databases do not have support for
initial privileges via pg_init_privs, we need to repeat again the same
ACL reordering method.

ACL for databases have been moved from pg_dumpall to pg_dump in v11, so
this impacts pg_dump for v11 and above, and pg_dumpall for v9.6 and
v10.

Discussion: https://postgr.es/m/15788-4e18847520ebcc75@postgresql.org
Author: Nathan Bossart
Reviewed-by: Haribabu Kommi
Backpatch-through: 9.6