MDEV-20091 DROP TEMPORARY table is logged despite no CREATE was logged

MDEV-5589 commit set up a policy to skip DROP TEMPORARY TABLE binary logging
in case the target table has not been "CREATEed" in binlog (no CREATE
Query-log-event was logged into the binary log).

It turns out that

1. the rule did not cover non-existing table DROPped with IF-EXISTS clause.
   The logged-create knowledge for the non-existing one does not even need
   MDEV-5589 patch, and

2. connection close disobeys it to trigger automatic DROP-IF-EXISTS
   binlogging.

Either 1 or 2 or even both is/are also responsible for unexpected binlog
records observed in MDEV-17863, actually rendering a referred
@@global.read_only irrelevant as far as the described stored procedure
definition *and* the ROW binlog-format are concerned.

mysql-test/include/binlog_parallel_replication_marks.test

@@ -49,9 +49,16 @@ connection default;
 
 # We need to wait for the implicit DROP TEMPORARY TABLE to be logged after
 # tmp_con disconnect, otherwise we get sporadic test failures.
+# MDEV-20091: DROP TEMPORARY TABLE IF EXISTS statements will be written to
+# binlog only if the corresponding temporary table exists. In row based
+# replication temporary tables are not replicated hence their corresponding
+# DROP TEMPORARY TABLE statement will be not be written to binary log upon
+# session closure.
+
+if (!`SELECT @@BINLOG_FORMAT = 'ROW'`) {
 --let $wait_condition= SELECT variable_value > $before_drop_pos FROM information_schema.global_status WHERE variable_name = 'binlog_snapshot_position'
 --source include/wait_condition.inc
-
+}
 --let $binlog_pos2=query_get_value(SHOW MASTER STATUS, Position, 1)
 
 --let $binlog_file= query_get_value(SHOW MASTER STATUS, File, 1)