Bug 19674: Broken indicators of changed fields in manage staged MARC records template

Bug 19674: Broken indicators of changed fields in manage staged MARC records template

This patch returns some CSS to the manage staged MARC records template
which was incorrectly removed by Gug 16538.

To test, apply the patch and go to Tools -> Staged MARC management.
Choose a staged MARC file.

Changing any of the <select> fields in the first section should cause a
label to appear showing that the selection has changed, along with a
link to reset the option to its original state. Clicking 'Reset' should
make the label and the link disappear.

Signed-off-by: Claire Gravely <claire.gravely@bsz-bw.de>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>