change available_models to return List[Model], previously List[str]

[mattf]

Description

make NVIDIAMultiModal.available_models consistent with other implementations.

New Package?

Did I fill in the tool.llamahub section in the pyproject.toml and provide a detailed README.md for my new integration or package?

• Yes
• No

Version Bump?

Did I bump the version in the pyproject.toml file of the package I am updating? (Except for the llama-index-core package)

• Yes
• No

Type of Change

Please delete options that are not relevant.

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

Your pull-request will likely not be merged unless it is covered by some form of impactful unit testing.

• I added new unit tests to cover this change
• I believe this change is already covered by existing unit tests

Suggested Checklist:

• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have added Google Colab support for the newly added notebooks.
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• I ran make format; make lint to appease the lint gods

[mattf]

@raspawar ptal

[raspawar]

lgtm!

[mattf]

unit test coverage -

---------- coverage: platform linux, python 3.10.15-final-0 ----------
Name                                              Stmts   Miss  Cover
---------------------------------------------------------------------
llama_index/multi_modal_llms/nvidia/__init__.py       2      0   100%
llama_index/multi_modal_llms/nvidia/base.py         189    134    29%
llama_index/multi_modal_llms/nvidia/utils.py        157    133    15%
---------------------------------------------------------------------
TOTAL                                               348    267    23%

integration test coverage -

---------- coverage: platform linux, python 3.10.15-final-0 ----------
Name                                              Stmts   Miss  Cover
---------------------------------------------------------------------
llama_index/multi_modal_llms/nvidia/__init__.py       2      0   100%
llama_index/multi_modal_llms/nvidia/base.py         189     21    89%
llama_index/multi_modal_llms/nvidia/utils.py        157     38    76%
---------------------------------------------------------------------
TOTAL                                               348     59    83%