[FIX] website, website_mass_mailing: fix parallax in modals

Before this commit "parallax" animation was not working in modals.

This commit adds a parameter to the animation effects to enable
animations (triggered by the scroll) in the modals.

Note that for the "Newsletter" popup we have hidden the "parallax"
options. To make them work, it would be necessary to review the
structure of the "Newsletter" popup so that the vertical scrollbar is in
the same location as the "s_popup" snippet (on the ".modal" element).

task-2971402

closes odoo/odoo#99894

Signed-off-by: Outagant Mehdi (mou) <mou@odoo.com>