[KYUUBI #2782][FOLLOWUP] Add missed UNION_TYPE back

This pull request fixes #
Fix https://github.com/apache/kyuubi/pull/6207#discussion_r1538539729

Please include a summary of the change and which issue is fixed. Please also include relevant motivation and context. List any dependencies that are required for this change.

- [ ] Bugfix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

---

- [ ] This patch was not authored or co-authored using [Generative Tooling](https://www.apache.org/legal/generative-tooling.html)

**Be nice. Be informative.**

Closes #6209 from turboFei/fix_union_type.

Closes #2782

622c838cd [Wang, Fei] miss

Authored-by: Wang, Fei <fwang12@ebay.com>
Signed-off-by: Wang, Fei <fwang12@ebay.com>
(cherry picked from commit ae9e88f0ca)
Signed-off-by: Wang, Fei <fwang12@ebay.com>

kyuubi-hive-jdbc/src/main/java/org/apache/kyuubi/jdbc/hive/JdbcColumn.java

@@ -240,6 +240,8 @@ public class JdbcColumn {
         return "struct";
       case NULL_TYPE:
         return "void";
+      case UNION_TYPE:
+        return "uniontype";
       default:
         throw new KyuubiSQLException("Invalid column type: " + type);
     }