chore: import upstream snapshot with attribution

samples/cpp/tutorial_code/imgcodecs/animations.cpp

@@ -0,0 +1,51 @@
+#include <opencv2/highgui.hpp>
+#include <opencv2/imgcodecs.hpp>
+#include <opencv2/imgproc.hpp>
+#include <iostream>
+
+using namespace cv;
+
+int main( int argc, const char** argv )
+{
+    std::string filename = argc > 1 ? argv[1] : "animated_image.webp";
+
+    //! [write_animation]
+    if (argc == 1)
+    {
+        Animation animation_to_save;
+        Mat image(128, 256, CV_8UC4, Scalar(150, 150, 150, 255));
+        int duration = 200;
+
+        for (int i = 0; i < 10; ++i) {
+            animation_to_save.frames.push_back(image.clone());
+            putText(animation_to_save.frames[i], format("Frame %d", i), Point(30, 80), FONT_HERSHEY_SIMPLEX, 1.5, Scalar(255, 100, 0, 255), 2);
+            animation_to_save.durations.push_back(duration);
+        }
+        imwriteanimation("animated_image.webp", animation_to_save, { IMWRITE_WEBP_QUALITY, 100 });
+    }
+    //! [write_animation]
+
+    //! [init_animation]
+    Animation animation;
+    //! [init_animation]
+
+    //! [read_animation]
+    bool success = imreadanimation(filename, animation);
+    if (!success) {
+        std::cerr << "Failed to load animation frames\n";
+        return -1;
+    }
+    //! [read_animation]
+
+    //! [show_animation]
+    while (true)
+    for (size_t i = 0; i < animation.frames.size(); ++i) {
+        imshow("Animation", animation.frames[i]);
+        int key_code = waitKey(animation.durations[i]); // Delay between frames
+        if (key_code == 27)
+            exit(0);
+    }
+    //! [show_animation]
+
+    return 0;
+}