[FIX] *: share URL on the correct website if possible

* = base, auth_signup, mail, portal, sale, website, website_sale

Before this commit, sending an object by email would always link to web.base.url
even if the object was created from a specific website.

Now if the object has a website, we use the URL of that website if it is set.
The fallback will always be on the web.base.url.

opw-1921030
PR: #30000