When the quantity on hand is updated from the wizard, it may result in
completely inconsistent results.
This happens for example in the following case:
- 10 Units in Stock/WH
- 18 Units in Stock/WH/Shelf 1
The "New Quantity on Hand" suggests a theoretical quantity by taking
into account the location and its sub-locations. It the example, that
would mean 28 Units in location 'Stock/WH'.
However, the `_get_quants` method of the `stock.inventory.line` model
doesn't take into account the children locations. Therefore, the
theoretical quantity would be 10 Units in location 'Stock/WH'.
This inconsistency confuses the user, and the new quantity added might
introduce unexpected results.
opw-703886