[IMP] split state field in two boolean fields with the same feature in b...

with the same feature in base delivery_carrier_label

validated on https://code.launchpad.net/~akretion-team/carriers-deliveries/7-split-default-option-state-from-deliv-method-dbl/+merge/224027

this PR replace the previous closed
Operator position is a matter of taste here it can still be on start of second line