[FEATURE] Template for ML resource cleanup

Is your feature request related to a problem?

Currently, Flow Framework has several pre-configured templates for deploying remote models and creating corresponding connectors: https://docs.opensearch.org/latest/automating-configurations/workflow-templates/#supported-workflow-templates. However, there is
no similar template that allows cleanup of ML resources. This is needed for scenarios involving one-time autonomous actions that need to create resources during a setup step and tear them down after the action is completed.

What solution would you like?

Template that can roll back resources create by "model deployment" templates:

• undeploy model
• delete model
• delete model group
• delete connector

What alternatives have you considered?

Perform resource cleanup via individual API calls. This lowers user adoption because such operations require deeper knowledge of OpenSearch internals and are error-prone.

Do you have any additional context?

This new functionality would be helpful for search relevance experiment scenarios, when a user does not have a connector to an LLM but wants to use features like LLM-generated judgments: https://docs.opensearch.org/latest/search-plugins/search-relevance/
using-search-relevance-workbench

No source files or tests are named. Start by reviewing the supported workflow templates and the model-deployment templates referenced in the issue, then trace the existing resource APIs. Done means a cleanup template can undeploy the model and delete the model, model group, and connector.