doc: Use tags consistently in the tutorial chapter

Make more consistent use of <screen> and <programlisting>.

Author: Jürgen Purtz <juergen@purtz.de>
Discussion: https://www.postgresql.org/message-id/flat/158996922318.7035.10603922579567326239@wrigleys.postgresql.org

doc/src/sgml/query.sgml

@@ -564,14 +564,16 @@ SELECT *
 <programlisting>
 SELECT *
     FROM weather LEFT OUTER JOIN cities ON (weather.city = cities.name);
+</programlisting>
 
+<screen>
      city      | temp_lo | temp_hi | prcp |    date    |     name      | location
 ---------------+---------+---------+------+------------+---------------+-----------
  Hayward       |      37 |      54 |      | 1994-11-29 |               |
  San Francisco |      46 |      50 | 0.25 | 1994-11-27 | San Francisco | (-194,53)
  San Francisco |      43 |      57 |    0 | 1994-11-29 | San Francisco | (-194,53)
 (3 rows)
-</programlisting>
+</screen>
 
     This query is called a <firstterm>left outer
     join</firstterm> because the table mentioned on the left of the
@@ -612,13 +614,15 @@ SELECT W1.city, W1.temp_lo AS low, W1.temp_hi AS high,
     FROM weather W1, weather W2
     WHERE W1.temp_lo &lt; W2.temp_lo
     AND W1.temp_hi &gt; W2.temp_hi;
+</programlisting>
 
+<screen>
      city      | low | high |     city      | low | high
 ---------------+-----+------+---------------+-----+------
  San Francisco |  43 |   57 | San Francisco |  46 |   50
  Hayward       |  37 |   54 | San Francisco |  46 |   50
 (2 rows)
-</programlisting>
+</screen>
 
     Here we have relabeled the weather table as <literal>W1</literal> and
     <literal>W2</literal> to be able to distinguish the left and right side