[FLINK-28107][python][connector/elasticsearch] Support id of document is null

[a49a]

What is the purpose of the change

Support id of document is null

Brief change log

• Add IndexRequest in SimpleElasticsearchEmitter

Verifying this change

This change added tests and can be verified as follows:

• Added integration tests for end-to-end deployment with large payloads (100MB)

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): (yes)
• 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)

[flinkbot]

CI report:

• 0814dc1 Azure: SUCCESS
• 8e991e5 Azure: PENDING

Bot commands

The @flinkbot bot supports the following commands:

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

[dianfu]

@deadwind4 Thanks for the update! LGTM overall. I'm wondering if we should rename SimpleElasticsearchEmitter to MapElasticsearchEmitter to indicate that it actually accepts Map as input. What's your thought?

[a49a]

@dianfu make sense to me.