refactor: Improve error handling in CellMapImage

Improve error handling in the CellMapImage class by providing a fallback mechanism when unable to retrieve class counts from metadata. Instead of printing the error message, a more informative message is printed, indicating that the foreground will be assigned 1 pixel and the rest will be considered as background.

src/cellmap_data/image.py

@@ -341,7 +341,10 @@ def class_counts(self) -> float:
                 ) * np.prod(list(self.scale.values()))
                 self._bg_count = bg_count * np.prod(list(self.scale.values()))
             except Exception as e:
-                print(f"Error: {e}")
+                # print(f"Error: {e}")
+                print(
+                    "Unable to get class counts from metadata, falling back to giving foreground 1 pixel, and the rest to background."
+                )
                 self._class_counts = np.prod(list(self.scale.values()))
                 self._bg_count = (
                     np.prod(self.group[self.scale_level].shape) - 1