ADD functionality to retrieve and display clips by ID

src/main/java/com/ddf/vodsystem/services/ClipService.java

@@ -100,4 +100,8 @@ public class ClipService {
         clip.setVideoPath(outputFile.getPath());
         clipRepository.save(clip);
     }
+
+    public Clip getClipById(Long id) {
+        return clipRepository.findById(id).orElse(null);
+    }
 }