[FIX] website: delete page on cascade when deleting a website
[FIX] website: delete page on cascade when deleting a website

The user is never able to delete a website, since there is at least one page,
the homepage, which is bootstraped during website creation.
From that point, even if nothing was done on that website, it was not possible
to remove it.
As website deletion is already a technical thing (debug mode), and since
website.page do not make sense without their website, removing those on cascade
will allow the user to remove a non-modified website.

task-2092845

closes odoo/odoo#45018

X-original-commit: ba6206baae7e3defbb6d28bcfe48eb5bed38d4c7
Signed-off-by: Romain Derie <a9a1578f1a6d5b390f1e6505f5f716509d49a3ed@users.noreply.github.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo