Add blocking view

[Nemandza82]

To support operations which take multiple consecutive elements of input collection and/or generate multiple consecutive elements of output collection, Symd bust have something like blocking view.

Examples of such operations are for instance color conversions. Here is example usage of such view:

    size_t width = 1920;
    size_t height = 1080;
    
    std::vector<float> YUV444(width * height * 3);
    std::vector<float> RGB24_mc(YUV444.size());

    symd::map(symd::views::block_view<3,1>(RGB24_mc), [](auto yuv)
          {
                return yuvToRgbKernel(yuv[1], yuv[0], v[2]);

          }, symd::views::block_view<3,1>(YUV444));

symd::views::block_view<3,1>(YUV444) creates block view of input collection where blocks are of 3x1 size.

Optimal implementation could be achieved by implementing block_view, and overriding all necessary view operations (getWidth, getHeight, getPitch, fetchData, fetchVecData, saveData, saveVecData and more).

Fetch and save methods should fetch and save all elements within block so they are accessible within the kernel.

For this we added failing test:

TEST_CASE("Mapping - blocking input YUV444 to RGB")

Which after correct implementation should pass.