feat: Refactor LLM model zoo and add KV cache support

[peri044]

Description

This PR redesigns our LLM model compilation, unifies it, fixes output mismatch and performance issues. This PR also implements KV caching using native TensorRT.

Fixes # (issue)

Type of change

• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist:

• My code follows the style guidelines of this project (You can use the linters)
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas and hacks
• I have made corresponding changes to the documentation
• I have added tests to verify my fix or my feature
• New and existing unit tests pass locally with my changes
• I have added the relevant labels to my PR in so that relevant reviewers are notified

[zewenli98]

Mostly LGTM. just some questions

[zewenli98]

same questions above

[narendasan]

LGTM only suggestion is moving tests into a tests subdirectory or into the tests directory. Is optional.