fix styles + remove duplication for the AI Chat component

[iamfaran]

Proposed changes

This PR fixes the AI Chat LLM component default styles for the assistant messages

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• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation Update (if none of the other choices apply)

Checklist

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• Lint and unit tests pass locally with my changes
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