Bug 25658: Print icon sometimes obscures patron barcode

Bug 25658: Print icon sometimes obscures patron barcode

This patch alters the style of the patron name/cardnumber label on the
checkout screen so that it has a maximum width. This will help avoid the
label being obscured by the print/close buttons displayed when
DisplayClearScreenButton is enabled.

To test, apply the patch and rebuild the staff client CSS
(https://wiki.koha-community.org/wiki/Working_with_SCSS_in_the_OPAC_and_staff_client).

 - Enable the DisplayClearScreenButton system preference.
 - Check out to a patron. Resize the browser to confirm that at narrower
   browser widths the patron name in the checkout form isn't obscured by
   the print and clear screen buttons.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Alex Arnaud <alex.arnaud@biblibre.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>