[FW][ADD] website_sale_order_validity: add new module

[fw-bot-adhoc]

Forward-Port-Of: ingadhoc/website#279

[roboadhoc]

Pull request status dashboard.

[fw-bot-adhoc]

@lef-adhoc @matiasperalta1 this PR targets 17.0 and is the last of the forward-port chain.

To merge the full chain, use

@fw-bot-adhoc r+

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[fw-bot-adhoc]

@lef-adhoc @matiasperalta1 ci/runbot-oba failed on this forward-port PR

[fw-bot-adhoc]

@lef-adhoc @matiasperalta1 this PR was modified / updated and has become a normal PR. It should be merged the normal way (via @roboadhoc)

[lef-adhoc]

@roboadhoc r+