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/android/tutorial-2-mixedprocessing/build.gradle.in

@@ -0,0 +1,43 @@
+apply plugin: 'com.android.application'
+
+android {
+    compileSdkVersion @ANDROID_COMPILE_SDK_VERSION@
+    defaultConfig {
+        applicationId "org.opencv.samples.tutorial2"
+        minSdkVersion @ANDROID_MIN_SDK_VERSION@
+        targetSdkVersion @ANDROID_TARGET_SDK_VERSION@
+        versionCode 301
+        versionName "3.01"
+
+        externalNativeBuild {
+            cmake {
+                arguments "-DOpenCV_DIR=" + project(':opencv').projectDir + "/@ANDROID_PROJECT_JNI_PATH@"@OPENCV_ANDROID_CMAKE_EXTRA_ARGS@
+                targets "mixed_sample"
+            }
+        }
+    }
+    buildTypes {
+        release {
+            minifyEnabled false
+            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
+        }
+    }
+    sourceSets {
+        main {
+            java.srcDirs = @ANDROID_SAMPLE_JAVA_PATH@
+            aidl.srcDirs = @ANDROID_SAMPLE_JAVA_PATH@
+            res.srcDirs = @ANDROID_SAMPLE_RES_PATH@
+            manifest.srcFile '@ANDROID_SAMPLE_MANIFEST_PATH@'
+        }
+    }
+    externalNativeBuild {
+        cmake {
+             path '@ANDROID_SAMPLE_JNI_PATH@/CMakeLists.txt'
+        }
+    }
+}
+
+dependencies {
+    //implementation fileTree(dir: 'libs', include: ['*.jar'])
+    implementation project(':opencv')
+}