Enhance the tool calling notebook to avoid interaction while running the notebook

[puhuim]

Enhance the tool calling notebook to avoid interaction while running the notebook
Updating:

1. Add a waiting function in 2_finetuning_and_inference.ipynb to wait customizer job to finish.
2. Set CUSTOM_MODEL in nemo/data-flywheel/tool-calling/config.py and use this variable as the fine-tuned model name in all notebooks. Avoid setting the fine-tuned model name manually in 3_model_evaluation.ipynb and 4_adding_safety_guardrails.ipynb
3. Update namespace from "default\" to NMS_NAMESPACE for guardrail config in 4_adding_safety_guardrails.ipynb to ensure all test resources are in the same namespace