ggml-cuda: Add NVFP4 dp4a kernel (#20644)
Added check for dst_t to cuda_cast template for float
Restored ggml_cuda_ue4m3_to_fp32, changed vecdot ints to int32ts
Added CUDART/HIP Check and HIP/fp8 include
Added NVFP4 to Test-backend-ops
Added hip_fp8_e4m3 to __nv_fp8_e4m3 typedef
---------
Co-authored-by: Johannes Gäßler <johannesg@5d6.de>
