[Kernel] Support W8A8 channel-wise weights and per-token activations in triton fused_moe_kernel

[mgoin]

Adapting in updates to the triton fused_moe kernel to expand the supported quantization formats

This PR enables:

• W8A8 FP8 for channel-wise weights and per-token activations
• W8A8 INT8 for channel-wise weights and per-token activations
• W8A8 INT8 for blocked weights and blocked per-token activation (like FP8 for DeepSeek)

Thank you to the sglang team for these developments pushing open source inference forward

[github-actions]

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[bnellnm]

There's a lot of commonality in the test files w/test_block_fp8.py. Would it be possible to move some of it to a common utility file?