Before this commit, when hovering the shopping cart in the "Boxed" and
"Centered Logo" header templates, the cart popover was not appearing.

This happened because the `websiteSaleCartLink` public widget was never
started with these templates and so, hovering the cart had no effect.
This is due to this widget selector which targeted a cart link located
inside an element with id `#top_menu`, which is not the case in these
templates where the cart link is located outside of it.

This commit fixes this widget selector, in order for the cart link to be
reachable in all header templates.

opw-3267114

closes odoo/odoo#118822

Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>