Bug 19708: Improve code for printing the cart in OPAC

Bug 19708: Improve code for printing the cart in OPAC

This removes a lot of useless code relating to the print function from opac-basket.tt, opac-basket.pl and opac/basket.js.

It also fixes the CSS so that no extra blank page is printed.

To test:
0) Add an item to your cart
1) Print your basket
    Note the appearance of the page. There will be an extra blank page.
2) Apply patch
3) Reload basket
4) Print your basket
    The appearce should be identical. The extra blank page is gone.

This only affects the OPAC.

Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: claude <claude.brayer@cea.fr>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>