[FIX] update tests and change search logic (webclient)

previous commit broke some tests.  The issue is that the search view
now avoid making requests if there is no action id.  But this is an
assumption that tests use, so some slight adjustments have to be made.

Also, this is the moment to give properly the action id to the favorite
menu.  Instead of bypassing its parent, it now receives the action id
from the search view.
[IMP] portal_sale, sale, website_quote: display the payment
button in emails only if there is an amount to pay. Free orders
exist (free events for example).

[IMP] website_sale: pay now is now confirm order if the sale order
amount is 0. Also improved the confirmation message in the checkout
process.