feat : support for conv3D forward

for (DimSize_t kX = 0; kX < kDim[0]; ++kX) {
    kOffsets[2] = kX * kStrides[2] + kOffsets[1];
    iDilKernelOffsets[0] = kX * dilation[0] * iStrides[2];

    // DOING STUFF ...........
}

iDilKernelOffsets[0] = 0;
kOffsets[2] = kOffsets[1];
for (DimSize_t kX = 0; kX < kDims[0]; ++kX,
               kOffsets[2] += kStrides[2],
               iDilKernelOffsets[0] += dilation[0] *
                                       iStrides[2]) {
    // DOING STUFF ...........
}

for (DimSize_t kX = 0; kX < kDims[0]; ++kX) {
    // DOING STUFF ...........
    kOffsets[2] += kStrides[2];
    iDilKernelOffsets[0] += dilation[0] * iStrides[2];
}