[FEATURE] Add flow function and example of calling LLM to extract data

[badmonster0]

What is the use case?
Integrate with LLM to extract (semi) structured data from unstructured documents.

Describe the solution you'd like
A clear and concise description of what you want to happen.

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.