8.0 port module stock_reserve_sale

Includes re-factoring with new API

This PR depends on https://github.com/OCA/stock-logistics-warehouse/pull/8 which is merged :smile_cat: 
you can remove the [0] by changing the decorator of the function from `api.one` to `api.multi` (use `self.ensure_one()` at the beginning of the method if needed)