Add default configuration to pgpool to avoid split braining

[plirglo]

Is your feature request related to a problem? Please describe.

In some conditions there is possibility of split braining in PostgreSQL cluster. This might ocurre when primary server goes down, secondary one is promoted to be a primary, and old primary starting up and is re-connected to cluster. We need to add configuration to avoid such cases.

Describe the solution you'd like Please find solution. Maybe watchdog configuration.

Describe alternatives you've considered Create script to remove server from repmgr cluster in case of failure.

Additional context See this article.

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DoD checklist

• Changelog
  • [ ] updated
  • [ ] not needed
• COMPONENTS.md
  • [ ] updated
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• Schema
  • [ ] updated
  • [ ] not needed
• Backport tasks
  • [ ] created
  • [ ] not needed
• Documentation
  • [ ] added
  • [ ] updated
  • [ ] not needed
• [ ] Feature has automated tests
• [ ] Automated tests passed (QA pipelines)
  • [ ] apply
  • [ ] upgrade
  • [ ] backup/restore
• [ ] Idempotency tested
• [ ] All conversations in PR resolved
• [ ] Solution meets requirements and is done according to design doc
• [ ] Usage compliant with license