Provide a way for Image / Document caching for supported Platforms

[bjalt]

When processing large images or documents (file) with every request the files is send as encoded data. This increases the token usage since every time the file needs to be ingested again. Especially with Tool Calling this leads to a high usage of tokens.

To mitigate this issues some platforms provide a way to cache input files. It would be nice to fine a way to enable caching.

For Reference Purposes:

• https://docs.anthropic.com/en/docs/build-with-claude/prompt-caching
• https://docs.aws.amazon.com/bedrock/latest/userguide/prompt-caching.html
• https://platform.openai.com/docs/guides/prompt-caching
  • Prompt Caching is activated by default for OpenAI

[bjalt]

See also #317. That issue might be related though it specifically provides an example for tool calling. I'm more interested in caching large portions of prompt content.

[chr-hertel]

Sounds like a good addition - would be great if LLM Chain can handle that right away 👍