[fix](routine load) fix show routine load task result incorrect (#38523) (#38826)

pick (#38523)

Create a job:
```
CREATE ROUTINE LOAD testShow ON test_show_routine_load
COLUMNS TERMINATED BY ","
PROPERTIES
(
"max_batch_interval" = "5",
"max_batch_rows" = "300000",
"max_batch_size" = "209715200"
)
FROM KAFKA
(
"kafka_broker_list" = "127.0.0.1:19092",
"kafka_topic" = "test_show_routine_load",
"property.kafka_default_offsets" = "OFFSET_BEGINNING"
);
```
show routine load task:
```
SHOW ROUTINE LOAD TASK WHERE JobName = "testShow";
```
result:
```
ERROR 1105 (HY000): errCode = 2, detailMessage = The job named testshowdoes not exists or job state is stopped or cancelled
```

Do not  use `toLowerCase` method;

fe/fe-core/src/main/java/org/apache/doris/analysis/ShowRoutineLoadTaskStmt.java

@@ -121,7 +121,7 @@ public class ShowRoutineLoadTaskStmt extends ShowStmt {
                 break CHECK;
             }
             StringLiteral stringLiteral = (StringLiteral) binaryPredicate.getChild(1);
-            jobName = stringLiteral.getValue().toLowerCase();
+            jobName = stringLiteral.getValue();
         } // CHECKSTYLE IGNORE THIS LINE
 
         if (!valid) {