[Tenable IO] Add support for new ratings object and vulnerability scoring metrics

[moxarth-rathod]

Proposed commit message

tenable_io: add support for new ratings object in asset data stream and vulnerability scoring metrics in vulnerability data stream

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.
• I have verified that any added dashboard complies with Kibana's Dashboard good practices

How to test this PR locally

• Clone integrations repo.
• Install elastic package locally.
• Start elastic stack using elastic-package.
• Move to integrations/packages/tenable_io directory.
• Run the following command to run tests.

elastic-package test

Related issues

• Closes [tenable_io] Add support for new ratings object and vulnerability scoring metrics #15516

[elasticmachine]

Pinging @elastic/security-service-integrations (Team:Security-Service Integrations)

[elastic-vault-github-plugin-prod]

🚀 Benchmarks report

To see the full report comment with /test benchmark fullreport

[elasticmachine]

💚 Build Succeeded

• Buildkite Build
• Commit: 5be9eab

cc @moxarth-rathod