feat: 切换后端至PaddleOCR-NCNN，切换工程为CMake

1.项目后端整体迁移至PaddleOCR-NCNN算法，已通过基本的兼容性测试
2.工程改为使用CMake组织，后续为了更好地兼容第三方库，不再提供QMake工程
3.重整权利声明文件，重整代码工程，确保最小化侵权风险

Log: 切换后端至PaddleOCR-NCNN，切换工程为CMake
Change-Id: I4d5d2c5d37505a4a24b389b1a4c5d12f17bfa38c

3rdparty/ncnn/tools/pnnx/cmake/PNNXPyTorch.cmake

@@ -0,0 +1,32 @@
+# reference to https://github.com/llvm/torch-mlir/blob/main/python/torch_mlir/dialects/torch/importer/jit_ir/cmake/modules/TorchMLIRPyTorch.cmake
+
+# PNNXProbeForPyTorchInstall
+# Attempts to find a Torch installation and set the Torch_ROOT variable
+# based on introspecting the python environment. This allows a subsequent
+# call to find_package(Torch) to work.
+function(PNNXProbeForPyTorchInstall)
+  if(Torch_ROOT)
+    message(STATUS "Using cached Torch root = ${Torch_ROOT}")
+  elseif(Torch_INSTALL_DIR)
+    message(STATUS "Using cached Torch install dir = ${Torch_INSTALL_DIR}")
+    set(Torch_DIR "${Torch_INSTALL_DIR}/share/cmake/Torch" CACHE STRING "Torch dir" FORCE)
+  else()
+    #find_package (Python3 COMPONENTS Interpreter Development)
+    find_package (Python3)
+    message(STATUS "Checking for PyTorch using ${Python3_EXECUTABLE} ...")
+    execute_process(
+      COMMAND "${Python3_EXECUTABLE}"
+      -c "import os;import torch;print(torch.utils.cmake_prefix_path, end='')"
+      WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+      RESULT_VARIABLE PYTORCH_STATUS
+      OUTPUT_VARIABLE PYTORCH_PACKAGE_DIR)
+    if(NOT PYTORCH_STATUS EQUAL "0")
+      message(STATUS "Unable to 'import torch' with ${Python3_EXECUTABLE} (fallback to explicit config)")
+      return()
+    endif()
+    message(STATUS "Found PyTorch installation at ${PYTORCH_PACKAGE_DIR}")
+
+    set(Torch_ROOT "${PYTORCH_PACKAGE_DIR}" CACHE STRING
+        "Torch configure directory" FORCE)
+  endif()
+endfunction()