[FLINK-28655][SQL gateway] Support show jobs operation in SqlGateway

[link3280]

What is the purpose of the change

Support show jobs statement in SqlGatewayService. Subtask of FLIP-222.

Brief change log

• Add show jobs statement in SQL parser.
• Add show jobs operation support in the table planner.
• Add show jobs operation support in SQL gateway.

Verifying this change

This change added tests and can be verified as follows:

• Extend FlinkSqlParserImplTest to validate the parsing of show-jobs statements.
• Extend SqlGatewayServiceITCase to validate the execution of show-jobs statements.

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? yes
• If yes, how is the feature documented? (not applicable / docs / JavaDocs / not documented)

[flinkbot]

CI report:

• 63457f9 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

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

[link3280]

@flinkbot run azure

[link3280]

@flinkbot run azure

[link3280]

Please kindly take a look @fsk119 .

[LadyForest]

Hi @link3280, thanks for the contribution. I hope you don't mind an unsolicited review.
I left some questions that are not clear to me from the FLIP doc.

[link3280]

I hope you don't mind an unsolicited review.

No, absolutely not! Thanks a lot for your review! @LadyForest

[fsk119]

Thasnks for your update. I left some comments.

[link3280]

@fsk119 Thanks a lot for your review! The PR is updated as suggested.

[fsk119]

LGTM

[LadyForest]

Thanks for the update; looks good to me too.

[link3280]

Thanks a lot! @LadyForest @fsk119