add nvidia distribution

[cdgamarose-nv]

What does this PR do?

adds nvidia template for creating a distribution using inference adapter for NVIDIA NIMs.

Test Plan

Please describe:
Build llama stack distribution for nvidia using the template, docker and conda.

llama stack build --template nvidia

or

cd distributions/inline-nvidia/ && docker compose up

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Ran pre-commit to handle lint / formatting issues.
• Read the contributor guideline,
  Pull Request section?
• Updated relevant documentation.
• Wrote necessary unit or integration tests.

[cdgamarose-nv]

@mattf for viz