MDEV-9592 - New 'Normal shutdown' log format can be confusing

Elaborate shutdown message.

mysql-test/r/shutdown.result

@@ -13,4 +13,4 @@ drop user user1@localhost;
 #
 # MDEV-8491 - On shutdown, report the user and the host executed that.
 #
-FOUND 2 /mysqld(\.exe)? \(root\[root\] @ localhost \[(::1)?\]\): Normal shutdown/ in mysqld.1.err
+FOUND 2 /mysqld(\.exe)? \(initiated by: root\[root\] @ localhost \[(::1)?\]\): Normal shutdown/ in mysqld.1.err

mysql-test/t/shutdown.test

@@ -34,5 +34,5 @@ drop user user1@localhost;
 --echo # MDEV-8491 - On shutdown, report the user and the host executed that.
 --echo #
 --let SEARCH_FILE= $MYSQLTEST_VARDIR/log/mysqld.1.err
---let SEARCH_PATTERN=mysqld(\.exe)? \(root\[root\] @ localhost \[(::1)?\]\): Normal shutdown
+--let SEARCH_PATTERN=mysqld(\.exe)? \(initiated by: root\[root\] @ localhost \[(::1)?\]\): Normal shutdown
 --source include/search_pattern_in_file.inc

sql/share/errmsg-utf8.txt

@@ -1807,7 +1807,7 @@ ER_NORMAL_SHUTDOWN
         cze "%s (%s): normální ukončení"
         dan "%s (%s): Normal nedlukning"
         nla "%s (%s): Normaal afgesloten "
-        eng "%s (%s): Normal shutdown"
+        eng "%s (initiated by: %s): Normal shutdown"
         est "%s (%s): MariaDB lõpetas"
         fre "%s (%s): Arrêt normal du serveur"
         ger "%s (%s): Normal heruntergefahren"
@@ -1822,7 +1822,7 @@ ER_NORMAL_SHUTDOWN
         pol "%s (%s): Standardowe zakończenie działania"
         por "%s (%s): 'Shutdown' normal"
         rum "%s (%s): Terminare normala"
-        rus "%s (%s): Корректная остановка"
+        rus "%s (инициирована пользователем: %s): Корректная остановка"
         serbian "%s (%s): Normalno gašenje"
         slo "%s (%s): normálne ukončenie"
         spa "%s (%s): Apagado normal"