Bug 18304: Do not mail cart or list contents to the library

Bug 18304: Do not mail cart or list contents to the library

Sometimes we receive mails from patrons, sent from opac-sendbasket or
opac-sendshelf. Instead of placing a hold on books they send the contents
of the cart (or even a list).

This patch simply puts a note on both forms saying that they should not
use the mail to request or renew books. If both options are disabled on
the OPAC, the message is not shown.

Test plan:
[1] Enable RequestOnOPAC.
[2] Put a book in the cart.
[3] Open the cart, click on Send. Verify presence of the message.
[4] Open a list.
[5] Click on Send list. Verify presence of the message.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jesse Maseto <jesse@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>