This is a base module that propagates the SO carrier to the procurement group.

Having the carrier on the procurement group allows to apply different routing
for each carrier thanks to the dynamic routing. A rule domain can then be
expressed based on the delivery carrier. See the module stock_dynamic_routing
in OCA/wms.

The carrier on the procurement group is also used for grouping several SO in a
same delivery by carrier. See the module
stock_picking_group_by_partner_by_carrier in this repository.
