Make test_decoding ddl.out shorter

Some of the test_decoding test output was extremely wide, because it
deals with massive toasted values, and the aligned mode causes psql to
produce 200kB of whitespace and dashes. Change to unaligned mode
temporarily to avoid that behavior.

Backpatch to 14, where it applies cleanly.

Discussion: https://postgr.es/m/20230405103953.sxleixp3uz5lazst@alvherre.pgsql

contrib/test_decoding/sql/ddl.sql

@@ -414,7 +414,11 @@ UPDATE toasttable
     SET toasted_col1 = (SELECT string_agg(g.i::text, '') FROM generate_series(1, 2000) g(i))
 WHERE id = 1;
 
+-- This output is extremely wide, and using aligned mode causes psql to
+-- produce 200kB of useless dashes. Turn that off temporarily to avoid it.
+\pset format unaligned
 SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
+\pset format aligned
 
 INSERT INTO toasttable(toasted_col1) SELECT string_agg(g.i::text, '') FROM generate_series(1, 2000) g(i);
 
@@ -426,10 +430,12 @@ WHERE id = 1;
 -- make sure we decode correctly even if the toast table is gone
 DROP TABLE toasttable;
 
+\pset format unaligned
 SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
 
 -- done, free logical replication slot
 SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
+\pset format aligned
 
 SELECT pg_drop_replication_slot('regression_slot');