Feat/support kafka bulk config

[gogodjzhu]

Type of change:

• Enhancement

Proposed commit message

Just add two Kafka output configurations to control bulk behavior.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
  • no need, just leave it empty to use default
• I have added tests that prove my fix is effective or that my feature works. Where relevant, I have used the stresstest.sh script to run them under stress conditions and race detector to verify their stability.
  • no need, just add a configuration for third party kafka sdk (sarama)
• I have added an entry in ./changelog/fragments using the changelog tool.

Disruptive User Impact

NO disruption by default.

Related issues

• Closes Kafka Output Bulk Flush Configuration Enhancement #48503

[cla-checker-service]

💚 CLA has been signed

[github-actions]

🤖 GitHub comments

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[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @gogodjzhu? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-8./d is the label to automatically backport to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[github-actions]

🔍 Preview links for changed docs

• docs/reference/filebeat/filebeat-reference-yml.md
• docs/reference/filebeat/kafka-output.md

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)