PG16: Handle new vacuum option ONLY_DATABASE_STATS

In order to properly process hypertables, chunks and compressed chunks we
run our own code when a VACUUM is executed.

PG16 introduced a new option named ONLY_DATABASE_STATS that only update
the database-wide statistics and when this option is specified no other
option may be enabled. Internally we build the list of all underlying
relations for hypertables in order to properly execute this utility
command leading to the following error:

test=# VACUUM (ONLY_DATABASE_STATS);
ERROR:  0A000: ONLY_DATABASE_STATS cannot be specified with a list of tables
LOCATION:  ExecVacuum, vacuum.c:369

Fixed it by properly handling the ONLY_DATABASE_STATS to don't execute
our modified vacuum code and instead the regular Postgres.

The error was catched up when running the `pginstallcheck` regression
tests.

postgres/postgres@a46a7011

src/process_utility.c

@@ -870,6 +870,22 @@ process_vacuum(ProcessUtilityArgs *args)
 
 	is_vacuumcmd = stmt->is_vacuumcmd;
 
+#if PG16_GE
+	if (is_vacuumcmd)
+	{
+		/* Look for new option ONLY_DATABASE_STATS */
+		foreach (lc, stmt->options)
+		{
+			DefElem *opt = (DefElem *) lfirst(lc);
+
+			/* if "only_database_stats" is defined then don't execute our custom code and return to
+			 * the postgres execution for the proper validations */
+			if (strcmp(opt->defname, "only_database_stats") == 0)
+				return DDL_CONTINUE;
+		}
+	}
+#endif
+
 	if (stmt->rels == NIL)
 		vacuum_rels = ts_get_all_vacuum_rels(is_vacuumcmd);
 	else