Add torch grouped gemm bf16 and mxfp8 support w/ cuda graphed + inference_optimized MoEs

[sidsingh-nvidia]

Note: Needs #3851 to go in first.

In main, we only support non-cudagraphed bf-16 only inference with torch grouped gemms. This PR introduces cuda-graphing and mxfp8 support for the same.

Limitation: Mxfp8 will only work with non-colocated RL, since TE and torch storage formats are slightly different.

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