Bug 4231 - Placing holds from cart fails silently

Bug 4231 - Placing holds from cart fails silently

This patch adds a more meaningfull message if multiple biblios with no
items attached are in the cart.

To test:
- Add biblios with and without items to cart
- Go to cart, select all and click 'Place hold'

Without patch, message reads:
Cannot place hold: this record has no items attached.

With patch, message reads:
Cannot place hold: one or more records without items attached.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>
Trivial string fix. Message is better than before.