[FIX] res.partner: propagate `is_supplier` property when creating parent or child partner for a supplier
[FIX] res.partner: propagate `is_supplier` property when creating parent or child partner for a supplier

This is not necessary for the `is_customer` flag, as it is
always True by default (customers are created more frequently).
Passing the field value via an invisible field in the mini
contact form is necessary because context `default_*` values are
automatically discarded by the ORM when creating o2m
or m2m records (as they are supposed to apply to a different model).
gisce/openobject-server,splbio/openobject-server,gisce/openobject-server,splbio/openobject-server,splbio/openobject-server,MarkusTeufelberger/openobject-server,MarkusTeufelberger/openobject-server,gisce/openobject-server,MarkusTeufelberger/openobject-server