feat(utils): add feature extraction utilities and tests

mini-nav/utils/__init__.py

@@ -1,3 +1,14 @@
 from .common import get_device, get_output_diretory
+from .feature_extractor import (
+    extract_batch_features,
+    extract_single_image_feature,
+    infer_vector_dim,
+)
 
-__all__ = ["get_device", "get_output_diretory"]
+__all__ = [
+    "get_device",
+    "get_output_diretory",
+    "infer_vector_dim",
+    "extract_single_image_feature",
+    "extract_batch_features",
+]