integrated vlm code for benchmark for Eagle2

[chohk88]

Description

Closing the previous pull request (#3652) due to rebase difficulties with the main branch. This new PR resubmits the same changes for the VLM benchmark framework—now cleanly rebased on the latest main branch—and incorporates all feedback from the original review.

1. Integrated VLM benchmark framework
   • Currently supports Eagle2
   • Planned support: Paligemma, Qwen 2.5-VL, etc.
2. Added custom token-generation function** for multi-modal (MM) models

Type of change

Please delete options that are not relevant and/or add your own.

• New feature (non-breaking change which adds functionality)

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