LockSegment absent of PostgreSQL parser 
## Bug Report

**For English only**, other languages will not accept.

Before report a bug, make sure you have:

- Searched open and closed [GitHub issues](https://github.com/apache/shardingsphere/issues).
- Read documentation: [ShardingSphere Doc](https://shardingsphere.apache.org/document/current/en/overview).

Please pay attention on issues you submitted, because we maybe need more details. 
If no response anymore and we cannot reproduce it on current information, we will **close it**.

Please answer these questions before submitting your issue. Thanks!

### Which version of ShardingSphere did you use?

5.0.0-RC1-SNAPSHOT

### Which project did you use? ShardingSphere-JDBC or ShardingSphere-Proxy?

ShardingSphere-JDBC

### Expected behavior

Under MasterSlave rule:

`SELECT * FROM t_order WHERE user_id = ? FOR UPDATE`

should be routed to Master node

### Actual behavior

The SQL is routed to Slave node

### Reason analyze (If you can)

LockSegment absent of PostgreSQL parser 

Please refer to the route logic in MasterSlaveDataSourceRouter:

 ```
    private boolean isMasterRoute(final SQLStatement sqlStatement) {
        return containsLockSegment(sqlStatement) || !(sqlStatement instanceof SelectStatement) || MasterVisitedManager.isMasterVisited() || HintManager.isMasterRouteOnly();
    }
    
    private boolean containsLockSegment(final SQLStatement sqlStatement) {
        return sqlStatement instanceof SelectStatement && ((SelectStatement) sqlStatement).getLock().isPresent();
    }
```

### Steps to reproduce the behavior, such as: SQL to execute, sharding rule configuration, when exception occur etc.

### Example codes for reproduce this issue (such as a github link).

diff --git a/shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/impl/PostgreSQLDMLVisitor.java b/shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/impl/PostgreSQLDMLVisitor.java
index 70d3050dab5..64eb9a8dfd6 100644
--- a/shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/impl/PostgreSQLDMLVisitor.java
+++ b/shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/impl/PostgreSQLDMLVisitor.java
@@ -28,6 +28,7 @@ import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.Co
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.DeleteContext;
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.DoStatementContext;
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.ExprListContext;
+import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.ForLockingClauseContext;
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.FromClauseContext;
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.FromListContext;
 import org.apache.shardingsphere.sql.parser.autogen.PostgreSQLStatementParser.GroupByItemContext;
@@ -326,6 +327,12 @@ public final class PostgreSQLDMLVisitor extends PostgreSQLVisitor implements DML
         return result;
     }
     
+    @Override
+    public ASTNode visitForLockingClause(final ForLockingClauseContext ctx) {
+        LockSegment result = new LockSegment(ctx.start.getStartIndex(), ctx.stop.getStopIndex());
+        return result;
+    }
+    
     @Override
     public ASTNode visitSelectWithParens(final SelectWithParensContext ctx) {
         if (null != ctx.selectWithParens()) {
['shardingsphere-sql-parser/shardingsphere-sql-parser-dialect/shardingsphere-sql-parser-postgresql/src/main/java/org/apache/shardingsphere/sql/parser/postgresql/visitor/impl/PostgreSQLDMLVisitor.java']