[Fix][Connector-V2] Fix postgres cdc with debezium_json format can not parse number without scale

[FrommyMind]

Purpose of this pull request

Fix #9037

Does this PR introduce any user-facing change?

No

How was this patch tested?

Updated E2E test cases.

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• 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 plugin-mapping.properties and add new connector information in it
  2. Update the pom file of seatunnel-dist
  3. Add ci label in label-scope-conf
  4. Add e2e testcase in seatunnel-e2e
  5. Update connector plugin_config
• Update the release-note.

[Hisoka-X]

Could you add a test case with compatible_debezium_json format in

seatunnel/seatunnel-e2e/seatunnel-connector-v2-e2e/connector-cdc-postgres-e2e/src/test/java/org/apache/seatunnel/connectors/seatunnel/cdc/postgres/PostgresCDCIT.java

Line 81 in 44e54c7

public class PostgresCDCIT extends TestSuiteBase implements TestResource {

[Hisoka-X]

Thanks @FrommyMind for update and added test case!

[Hisoka-X]

Does this change necessary? cc @hailin0

[FrommyMind]

I found that, the next is not null ,but next.value() maybe null when write data to kafka, so I change this.