[Kernel] Delegate construction of FusedMoEQuantConfig to FusedMoEMethodBase subclasses

[bnellnm]

Purpose

• Delegate construction of FusedMoEQuantConfig objects to the subclass of FusedMoEMethodBase that will use that info.
• Move all/most quantization info into FusedMoEQuantConfig and make it more uniform.
• Replace quantization parameters of fused_experts with a FusedMoEQuantConfig. This eliminates the various use_ bool flags and quantization parameters _scales, _zp, _bias, _gscale, etc.

Test Plan

• Run tests/kernels/moe
• Run lm_eval on affected MoE models.

Test Result

• TBD

(Optional) Documentation Update

• TODO: update modular kernel doc

cc @varun-sundar-rabindranath , @LucasWilkinson , @jeejeelee , @wenscarl , @nvpohanh , @mgoin

[gemini-code-assist]

Code Review

This pull request introduces a significant refactoring of the Mixture of Experts (MoE) quantization configuration by introducing a new FusedMoEQuantConfig structure. This is a positive change towards a more structured and extensible configuration. However, the refactoring appears to be incomplete, as there are several critical issues, including assert False statements, NotImplementedErrors, and usage of undefined variables in the new code paths. These issues will cause runtime failures and need to be addressed before this PR can be considered for merging. My review focuses on these critical issues.

[github-actions]

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[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @bnellnm.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @bnellnm.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[mergify]

This pull request has merge conflicts that must be resolved before it can be
merged. Please rebase the PR, @bnellnm.

https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/working-with-forks/syncing-a-fork

[minosfuture]

is this tested with mxfp4? @bnellnm

The test result section is still TBD.

[bnellnm]

is this tested with mxfp4? @bnellnm

The test result section is still TBD.

@minosfuture I think there was one issue with mxfp4 which has been fixed. I've not tested every possible combination but afaik everything should work.