[WIP] Add metadata capabilities to azure.ai.agents and azure.ai.finetune

[Copilot]

Thanks for assigning this issue to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add metadata capabilities to azure.ai.agents and azure.ai.finetune extensions</issue_title>
<issue_description>See #6496

We'll need to bump the github.com/azure/azure-dev/cli/azd dependency in go.mod</issue_description>

Comments on the Issue (you are @copilot in this section)

Custom agent used: Generate changelog (azd core)
Update azd core release changelog and version based on merged PRs.

• Fixes Add metadata capabilities to extensions #6539

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