Fused all_gather_fp8_gemm kernel implementation

[LironKesem]

I am migrating the all_gather_fp8_gemm implementation from vllm vllm-project/vllm#33933.

@shunting314 - would this be a useful addition to the core Helion repository? If yes, I can continue with cleanup and polishing.

[shunting314]

I think it make sense overall to add such a kernel to the helion repo. You also need add a test.

cc @choijon5 @jansel