feat(compare): add face comparison functionality with cosine similarity

src/facedet/retinaface.rs

@@ -310,7 +310,7 @@ pub trait FaceDetector {
     fn detect_faces(
         &mut self,
         image: ndarray::ArrayView3<u8>,
-        config: FaceDetectionConfig,
+        config: &FaceDetectionConfig,
     ) -> Result<FaceDetectionOutput> {
         let (height, width, _channels) = image.dim();
         let output = self