Revert "psql: Show all query results by default"

This reverts commit 3a51306722.

Per discussion, this patch had too many issues to resolve at this
point of the development cycle.  We'll try again in the future.

Discussion: https://www.postgresql.org/message-id/flat/alpine.DEB.2.21.1904132231510.8961@lancre

src/test/regress/sql/psql.sql

@@ -1241,41 +1241,3 @@ drop role regress_partitioning_role;
 \dfa bit* small*
 \do - pg_catalog.int4
 \do && anyarray *
-
---
--- combined queries
---
-CREATE FUNCTION warn(msg TEXT) RETURNS BOOLEAN LANGUAGE plpgsql
-AS $$
-  BEGIN RAISE NOTICE 'warn %', msg ; RETURN TRUE ; END
-$$;
--- show both
-SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
--- \gset applies to last query only
-SELECT 3 AS three \; SELECT warn('3.5') \; SELECT 4 AS four \gset
-\echo :three :four
--- syntax error stops all processing
-SELECT 5 \; SELECT 6 + \; SELECT warn('6.5') \; SELECT 7 ;
--- with aborted transaction, stop on first error
-BEGIN \; SELECT 8 AS eight \; SELECT 9/0 AS nine \; ROLLBACK \; SELECT 10 AS ten ;
--- close previously aborted transaction
-ROLLBACK;
--- misc SQL commands
--- (non SELECT output is sent to stderr, thus is not shown in expected results)
-SELECT 'ok' AS "begin" \;
-CREATE TABLE psql_comics(s TEXT) \;
-INSERT INTO psql_comics VALUES ('Calvin'), ('hobbes') \;
-COPY psql_comics FROM STDIN \;
-UPDATE psql_comics SET s = 'Hobbes' WHERE s = 'hobbes' \;
-DELETE FROM psql_comics WHERE s = 'Moe' \;
-COPY psql_comics TO STDOUT \;
-TRUNCATE psql_comics \;
-DROP TABLE psql_comics \;
-SELECT 'ok' AS "done" ;
-Moe
-Susie
-\.
-\set SHOW_ALL_RESULTS off
-SELECT 1 AS one \; SELECT warn('1.5') \; SELECT 2 AS two ;
-\set SHOW_ALL_RESULTS on
-DROP FUNCTION warn(TEXT);