Add DocumentUrl and support document via BinaryContent

[Kludex]

There are two model families that understand documents:

• Anthropic
  • https://docs.anthropic.com/en/docs/build-with-claude/citations
  • https://docs.anthropic.com/en/docs/build-with-claude/pdf-support
• Gemini: https://cloud.google.com/vertex-ai/generative-ai/docs/multimodal/document-understanding

The Anthropic models seems to give more insights than Gemini. We need to make decisions regarding the API given that.

The current implementation by the time I wrote this is not enough - it didn't include context, nor cache_control, nor citations from Anthropic.

[github-actions]

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