Bug 31813: Specify white-space: normal for spans styled as labels

Bug 31813: Specify white-space: normal for spans styled as labels

This patch is necessary to override a CSS property being inherited from
Bootstrap. Allowing a <span> with the "label" class to wrap will keep
alignment correct when displaying information in the same layout as a
form.

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

- If necessary, stage a batch of MARC files (Cataloging -> Stage MARC
  records for import).
- Go to Cataloging -> Manage staged MARC records and click on one of the
  batches to view the details.
- In the list of information about the batch, longer labels like
  "Matching rule applied" should wrap so that they stay aligned with
  other labels in the list.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>