[ADD] stock_sms: Integration with stock pickings

The user can already send a confirmation email when the
Stock Picking is done. It'd be great to communicate the
same information by SMS.

In addition, the current mailing tool requires a manual
action. The idea is to automate the process via a
Setting instead.

id=1972567

closes odoo/odoo#35662

Signed-off-by: Yannick Tivisse (yti) <yti@odoo.com>