feat: Support sarashina2.2-vision-3b model

[samuraieng]

Overview

This PR adds new PROJECTOR_TYPE to support for Sarashina2.2 Vision 3B model to llama.cpp, both llama-cli, llama-server and connvert_hf_to_gguf.py.
This implementation is updated to support the Sarashina model with minimum modifications.

Additional information

Changes

This PR updates six (6) files

• convert_hf_to_gguf.py
  • Add Sarashina2VisionForCausalLM
  • Add some logic to proceed Sarashina2.2-vision-3B model
• gguf-py/gguf/constants.py
  • Add SARASHINA2VL
• tools/mtmd/clip-impl.h
• tools/mtmd/clip.cpp
• tools/mtmd/mtmd.cpp
  • Add PROJECTOR_TYPE_SARASHINA2VL_MERGER
  • Modify switch-case to support the type
• tools/mtmd/tests.sh
  • Add sarashina2.2-vision-3b:Q4_K_M as add_test_vision

Testing

• ctest -L main passed
• tools/mtmd/tests.sh passed (with this modification)
• Manual test with using llama-cli and llama-server with following models
  • Sarashina2.2-vision-3b-gguf (Target to support)
  • Qwen3-VL-2B-Instruct-gguf (For regression testing)
  • Qwen2.5-VL-3B-Instruct (Locally converted to gguf, to check convert_hf_to_gguf.py)

Requirements

• I have read and agree with the contributing guidelines
• AI usage disclosure: YES - AI assisted with codeing. All code was human-authored, manually modified, reviewed and tested.

[CISC]

@samuraieng Bad merge.

[samuraieng]

Would you please review again? I think I captured all your comments in the latest update.

[CISC]

@samuraieng Bad merge.

[samuraieng]

Sorry for made this bad merge. I pushed again with new code. Would you please reviwe again?
As I wrote, only convert_hf_to_gguf.py is the file to review. Most of modification are made inside new classes.

[samuraieng]

Mostly, MMPROJ side was updated. The new class follows Qwen2VLVisionModel

[samuraieng]

@ngxson , would you please review the latest code?

[masabamba]

@ngxson , would you please review the latest code? The code I modified are same as before. Sync with the master branch.

[masabamba]

I updated to follow this review comment. Would you please review again?