Create LangGraph demo

[dylanbouchard]

Is your feature request related to a problem? Please describe.
Currently, UQLM is natively compatible with LangGraph, but we do not have any tutorials to illustrate this compatibility. To this end, we would like to create a simple tutorial notebook to illustrate using UQLM within an agentic workflow with LangGraph.

Is your feature request related to a problem? Please describe.

• Dataset: The data used should be either one of those offered by example_dataset_loader. If a new dataset is to be used, let's ensure it's available on HuggingFace and add it to the example_dataset_loader function.
• Notebook details: The notebook should be formatted in a similar way to the other notebooks and live in the /examples folder.
• Simplicity: The workflow should be minimal and illustrative. The purpose is to demonstrate compatibility, and simplicity should be prioritized when designing the example.

Additional context
Please note that LangGraph is not a requirement of UQLM. We are not looking to add new dependencies at this time. Please note in the notebook that installation of LangGraph is required before running the tutorial.

[vnnair98]

I'll take this one on