[feature][web-connector] Related code to adding DB2 connector in web

[haneeshmv]

Purpose of this pull request

Does this PR introduce any user-facing change?

How was this patch tested?

Check list

• [x] If any new Jar binary package adding in your PR, please add License Notice according New License Guide
• [x] If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• [ ] If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• [ ] Update the release-note.

[haneeshmv]

This PR is related to https://github.com/apache/seatunnel-web/pull/159

[Hisoka-X]

cc @hailin0

[haneeshmv]

@hailin0 @Hisoka-X

CI issues are fixed, could you please review ?

[hailin0]

@haneeshmv

Please reference OracleDataTypeConvertor

https://github.com/apache/seatunnel/blob/dev/seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/catalog/oracle/OracleDataTypeConvertor.java

Currently, DB2TypeConverter already exists, you can call it in Db2DataTypeConvertor.java.

https://github.com/apache/seatunnel/blob/dev/seatunnel-connectors-v2/connector-jdbc/src/main/java/org/apache/seatunnel/connectors/seatunnel/jdbc/internal/dialect/db2/DB2TypeConverter.java