[cdc-connector][db2] Db2 support incremental source

[gong]

Prepare a Pull Request

• Fixes #2869

Motivation

Db2 support incremental source

Modifications

• Add db2 incremental source code
• Add doc
• Add ITcase UT and e2e UT

[gong]

@leonardBang @GOODBOY008 PTAL

[gong]

@leonardBang test_1_ci_build core fail. because this PR https://github.com/ververica/flink-cdc-connectors/pull/2845 cause error. I rollback this change.

[gong]

random UT fail that is not relate with the db2

[lvyanquan]

Hi @gong There is a failure in https://dev.azure.com/ververica/flink-cdc-connectors/_build/results?buildId=4654&view=logs&j=450e5386-ec4e-5c3c-8d86-ea427d28cb6f&t=b72b380c-c1b9-55cc-a168-123a50838bbf, could you please take a look?

[gong]

Hi @gong There is a failure in https://dev.azure.com/ververica/flink-cdc-connectors/_build/results?buildId=4654&view=logs&j=450e5386-ec4e-5c3c-8d86-ea427d28cb6f&t=b72b380c-c1b9-55cc-a168-123a50838bbf, could you please take a look?

@lvyanquan ok

[gong]

LGTM. There is a mix of binlog redolog and wal in the code, it is best to unify them.

@lvyanquan ok

[gong]

I will rebase code after https://github.com/ververica/flink-cdc-connectors/pull/2978 is merged.

[gong]

@lvyanquan CI error is not related with the PR. UT can pass in local.

[leonardBang]

Thanks @gong for the great work, I'd like to have a final review base on @lvyanquan 's review work.

[leonardBang]

CI passed, merging...