make get_index_from_data_picked() return the list of indexes that the data...

make get_index_from_data_picked() return the list of indexes that the data point clicked represent for

sohstationviewer/view/plotting/plotting_widget/plotting_widget_helper.py

@@ -24,9 +24,7 @@ def get_index_from_data_picked(
     else:
         real_indexes = np.where((chan_data['times'][0] == tm) &
                                 (chan_data['data'][0] == val))[0]
-    if len(real_indexes) != 1:
-        return
-    return real_indexes[0]
+    return real_indexes
 
 
 def get_total_miny_maxy(