Prototype NVFP4 with FP8 UE5M3 block scales

[timmoon10]

Description

This is a proof-of-concept for NVFP4 with FP8 UE5M3 block scales. Quantization is supported, but GEMMs are not yet available.

Type of change

• Documentation change (change only to the documentation, either a fix or a new content)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Infra/Build change
• Code refactoring

Changes

• Support NVFP4 tensors with UE5M3 scales
• Support UE5M3 scales in NVFP4 quantize/dequantize kernels
• Support UE5M3 scales in NVFP4 quantizers

Checklist:

• I have read and followed the contributing guidelines
• The functionality is complete
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

[timmoon10]

/te-ci L1