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/opencv-4.5.4/samples/python/_doc.py

@@ -0,0 +1,25 @@
+#!/usr/bin/env python
+
+'''
+Scans current directory for *.py files and reports
+ones with missing __doc__ string.
+'''
+
+# Python 2/3 compatibility
+from __future__ import print_function
+
+from glob import glob
+
+if __name__ == '__main__':
+    print('--- undocumented files:')
+    for fn in glob('*.py'):
+        loc = {}
+        try:
+            try:
+                execfile(fn, loc)           # Python 2
+            except NameError:
+                exec(open(fn).read(), loc)  # Python 3
+        except Exception:
+            pass
+        if '__doc__' not in loc:
+            print(fn)