fix: unicode character in image path

src/arcaea_offline_ocr/utils.py

@@ -0,0 +1,9 @@
+from cv2 import IMREAD_UNCHANGED, Mat, imdecode
+from numpy import fromfile as np_fromfile
+from numpy import uint8
+
+
+def imread_unicode(filepath: str) -> Mat:
+    # https://stackoverflow.com/a/57872297/16484891
+    # CC BY-SA 4.0
+    return imdecode(np_fromfile(filepath, dtype=uint8), IMREAD_UNCHANGED)