[Meta] Refactoring data source plugin to support add-on authentication method with plug-in module

[bandinib-amzn]

This is meta tracking issue for Refactoring data source plugin to support add-on authentication method with plug-in module.

Tasks:

• Modify data_source and data_source_management plugin to register authentication method from plugin.
  PR for above task: [Multi data source] Add interfaces to register add-on authentication method from plug-in module #5851

• Refactoring client and legacy client to use authentication registry.
  PR for above task: Refactor getClient and getLegacyClient to use authentication method registry #5881

• Refactoring create and edit form to use authentication registry.

• [FEATURE] Add child client support AwsSigv4 opensearch-js#696

• Connection pooling support for AWSSigV4 clients/connection in data source #6114

[bandinib-amzn]

@xinruiba Can you please help on Refactoring create and edit form to use authentication registry? thanks!

[xinruiba]

@bandinib-amzn Sure, happy to work on it.

[xinruiba]

@bandinib-amzn, we can also mark "Refactoring create and edit form to use authentication registry." as complete. Thanks