Bug 23464: (follow-up) QA fixes

Bug 23464: (follow-up) QA fixes

This patch corrects two issues raised during testing:

 - Move JavaScript out of template check for IntranetUserJS so that
   SpineLabelAutoPrint behavior works correctly.
 - Add "close" button to pop-up window for cases when the barcode was
   not found.

Also changed:

- Added "required" attribute to barcode input on quick spine
  label printing page so that submitting an empty form will not work.

- Tweaked CSS slightly to fix alignment of spine label form and submit
  button. (You must rebuild the staff client CSS:
 https://wiki.koha-community.org/wiki/Working_with_SCSS_in_the_OPAC_and_staff_client)

Signed-off-by: Maryse Simard <maryse.simard@inlibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>