[FIX] mrp_multi_level: readd extensibility hook

_should_create_planned_order hook was unnoticely removed in
33cf4af as it was not needed
anymore in the base module. However it is still an extension point
that can be used.

mrp_multi_level/models/product_mrp_area.py

@@ -313,3 +313,7 @@ def _to_be_exploded(self):
     def _get_locations(self):
         self.ensure_one()
         return self.mrp_area_id._get_locations()
+
+    def _should_create_planned_order(self):
+        self.ensure_one()
+        return True

mrp_multi_level/wizards/mrp_multi_level.py

@@ -265,7 +265,9 @@ def create_planned_order(
             order_data = self._prepare_planned_order_data(
                 product_mrp_area_id, qty, mrp_date_supply, mrp_action_date, name, values
             )
-            planned_order = self.env["mrp.planned.order"].create(order_data)
+            planned_order = False
+            if product_mrp_area_id._should_create_planned_order():
+                planned_order = self.env["mrp.planned.order"].create(order_data)
             qty_ordered = qty_ordered + qty
 
             if product_mrp_area_id._to_be_exploded():