out_azure_kusto: Added workload identity support

[tanmaya-panda1]

This pull request introduces support for a new authentication method, "Workload Identity," in the Azure Kusto plugin. It includes updates to the configuration, authentication logic, and token management to accommodate this new method while maintaining compatibility with existing authentication types. Additionally, minor improvements and fixes are made to logging and code readability.

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Testing
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Backporting

• Backport to latest stable release.

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