add MNN/TNN/ONNXRuntime C++ demo

[DefTruth]

add MNN/TNN/ONNXRuntime C++ demo:

• Photo2Cartoon MNN C++
• Photo2Cartoon TNN C++
• Photo2Cartoon ONNXRuntime C++

usage

#include "lite/lite.h"

static void test_default()
{
  std::string head_seg_onnx_path = "../../../hub/onnx/cv/minivision_head_seg.onnx";
  std::string cartoon_onnx_path = "../../../hub/onnx/cv/minivision_female_photo2cartoon.onnx";
  std::string test_img_path = "../../../examples/lite/resources/test_lite_female_photo2cartoon.jpg";
  std::string save_mask_path = "../../../logs/test_lite_female_photo2cartoon_seg.jpg";
  std::string save_cartoon_path = "../../../logs/test_lite_female_photo2cartoon_cartoon.jpg";

  auto *head_seg = new lite::cv::segmentation::HeadSeg(head_seg_onnx_path, 4); // 4 threads
  auto *female_photo2cartoon = new lite::cv::style::FemalePhoto2Cartoon(cartoon_onnx_path, 4); // 4 threads

  lite::types::HeadSegContent head_seg_content;
  cv::Mat img_bgr = cv::imread(test_img_path);
  head_seg->detect(img_bgr, head_seg_content);

  if (head_seg_content.flag && !head_seg_content.mask.empty())
  {
    cv::imwrite(save_mask_path, head_seg_content.mask * 255.f);
    // Female Photo2Cartoon Style Transfer
    lite::types::FemalePhoto2CartoonContent female_cartoon_content;
    female_photo2cartoon->detect(img_bgr, head_seg_content.mask, female_cartoon_content);
    
    if (female_cartoon_content.flag && !female_cartoon_content.cartoon.empty())
      cv::imwrite(save_cartoon_path, female_cartoon_content.cartoon);
  }

  delete head_seg;
  delete female_photo2cartoon;
}

the output is: