[FLINK-27260][Runtime/REST] Expose changelog configurations in Rest API and Web UI

[fredia]

What is the purpose of the change

This PR wants to add two fields:

• changelog_storage
• changelog_periodic_materialization_interval

into the checkpoints-config response, and show these fields on web UI when changelog is enabled.

Brief change log

• Add changelog_storage and changelog_periodic_materialization_interval to rest api
• Add changelog_storage and changelog_periodic_materialization_interval to web ui

Verifying this change

Please make sure both new and modified tests in this PR follows the conventions defined in our code quality guide: https://flink.apache.org/contributing/code-style-and-quality-common.html#testing

This change is already covered by existing tests, such as (please describe tests).

• RestAPIStabilityTest

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with @Public(Evolving): (no)
• The serializers: ( no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• bede4ec Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[Myasuka]

@fredia would you please share the picture that how the UI looks like with this patch?

[fredia]

Sure. I run SocketWindowWordCount to get WEB UI. Here are pictures:

• when changelog enable, display changelog_storage and changelog_periodic_materialization_interval in checkpoint configuration tab:
  

• when changelog disable, don't show changelog_storage and changelog_periodic_materialization_interval:
  

[Myasuka]

Thanks for creating this PR, I think current PR looks in a good shape, please take a look at my comments.

[Myasuka]

Thanks for updating! Please take a look at my comments.

[Myasuka]

Thanks for the update. LGTM.

[Myasuka]

@flinkbot run azure