change(dataloader): concat_signal with mothers option to prevent buds

appearing twice in dataframe

dataloader.py

@@ -314,7 +314,9 @@ class dataloader:
             ):
                 print(" " + sigpath)
                 # load all cells
-                record = grouper.concat_signal(sigpath, cutoff=0)
+                record = grouper.concat_signal(
+                    sigpath, cutoff=0, mode="mothers"
+                )
                 # keep cells only in key_index
                 new_record = self.get_key_cells(record, key_index)
                 # interpolate to remove internal NaNs for signals from mothers