feat: Add Nvidia e2e beginner notebook and tool calling notebook

[JashG]

What does this PR do?

This PR contains two sets of notebooks that serve as reference material for developers getting started with Llama Stack using the NVIDIA Provider. Developers should be able to execute these notebooks end-to-end, pointing to their NeMo Microservices deployment.

1. beginner_e2e/: Notebook that walks through a beginner end-to-end workflow that covers creating datasets, running inference, customizing and evaluating models, and running safety checks.
2. tool_calling/: Notebook that is ported over from the Data Flywheel & Tool Calling notebook that is referenced in the NeMo Microservices docs. I updated the notebook to use the Llama Stack client wherever possible, and added relevant instructions.

Test Plan

• Both notebook folders contain READMEs with pre-requisites. To manually test these notebooks, you'll need to have a deployment of the NeMo Microservices Platform and update the config.py file with your deployment's information.
• I've run through these notebooks manually end-to-end to verify each step works.