Updated File explorer to work with large data directories

https://www.notion.so/qim-dtu/Improvement-for-the-FileExplorer-f7e564c4f3d649f8b8922a397648880d?pvs=4

qim3d/gui/data_explorer.py

@@ -408,7 +408,7 @@ class Pipeline:
                 dataset_name=session.dataset_name,
             )
             if session.vol.ndim != 3:
-                raise ValueError("Invalid data shape should be 3d: ", session.vol.shape)
+                raise ValueError("Invalid data shape should be 3 dimensional, not shape: ", session.vol.shape)
         except Exception as error_message:
             raise gr.Error(
                 f"Failed to load the image: {error_message}"