Revert "erp5_pdm: It is never the good solution to delete matrix cells directly."

This reverts commit ec926ea5.

This commit is still experimental, it was not supposed to be part of
this push.

bt5/erp5_pdm/WorkflowTemplateItem/portal_workflow/supply_line_interaction_workflow/scripts/SupplyLine_updateBasePricePerSlice.py

 supply_line = state_change['object']
-supply_line.updateQuantityPredicate(
-  'slice_base_price'
-  if supply_line.isBasePricePerSlice() else
-  'base_price'
-)
+to_delete_cell_list = [
+  cell for cell in supply_line.getCellIdList(base_id='path')
+  if hasattr(supply_line, cell)
+]
+supply_line.manage_delObjects(ids=to_delete_cell_list)
+if state_change.kwargs['workflow_method_args'][0]:
+  price_parameter = 'slice_base_price'
+else:
+  price_parameter = 'base_price'
+supply_line.updateQuantityPredicate(price_parameter)
 supply_line.updateCellRange(base_id='path')
-for cell_value in supply_line.getCellValueList(base_id='path'):
-  # XXX: only to trigger supply_cell_interaction_workflow/scripts/SupplyCell_updateSliceBasePrice
-  cell_value.setBasePrice(cell_value.getBasePrice())