[IMP] website_sale : Don't show shipping address when only services are into shopping cart.

Hello,
Hide the shipping address into website_sale module when cart has only service type products.

More Details:
Task : https://www.odoo.com/web#id=9420&view_type=form&model=project.task&menu_id=3942&action=327
Pad : https://pad.odoo.com/p/r.aJDvr5RhQPSR6xjV

Thanks
rsi-odoo
This sounds quite complicated... `get('key')` returns `None` by default (calling it twices is not useful)