[fix](function) Change digital_masking function arg type to BIGINT (#7888)

Change digital_masking function arg type to BIGINT to fix the wrong result.

docs/en/sql-reference/sql-statements/Data Definition/create-function.md

@@ -131,7 +131,7 @@ If the `function_name` contains the database name, the custom function will be c
 
     ```
     -- create a custom functional alias function
-    CREATE ALIAS FUNCTION id_masking(INT) WITH PARAMETER(id) 
+    CREATE ALIAS FUNCTION id_masking(BIGINT) WITH PARAMETER(id) 
         AS CONCAT(LEFT(id, 3), '****', RIGHT(id, 4));
 
     -- create a custom cast alias function