convert : add compressed-tensors NVFP4 support (#21095)
* Refactored Compressed Tensors NVFP4 support for new base.py
* Support compressed-tensors NVFP4 conversion
* Moved Qwen MTP remap into filter_tensors
* simplify
* pathlib no longer used
---------
Co-authored-by: Sigbjørn Skjæret <sigbjorn.skjaeret@scala.com>
