Bug 34553: Update send list and send cart popup footers

Bug 34553: Update send list and send cart popup footers

This patch updates the templates behind the "send cart" and "send list"
pop-ups in order to make the style of the footer consistent with some
recently-updated similar examples, like the catalog's Z39.50 search
popup.

The patch also makes a minor change to our global JavaScript include so
we can get away from using the "close" class as a trigger for closing a
pop-up window. Bootstrap has a built-in "close" class that we always
have to override. "close_window" is added as another class to use, and
the other instances can be cleaned up overy time.

To test, apply the patch and perform a catalog search in the staff
interface.

 - Add one or more items to the cart.
 - Open the cart popup and click the "Send" button.
 - In the pop-up window, confirm that the footer looks correct.
 - Test the process of using the tab key between input fields and
   submit/cancel buttons. All controls should be accessible.
 - Test the "Cancel" button to confirm that it closes the window.
 - Reopen the window and test sending the email.
 - On the confirmation page, confirm that the footer looks correct and
   that the "Close window" button works.

 - Test the same processes in the Lists module: View a list in the staff
   interface and test the process of sending a list.

Signed-off-by: Andrew Auld <andrew.auld@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>