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:

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