Bug 31928: Add page-section to callnumber browser value builder (cat)

Bug 31928: Add page-section to callnumber browser value builder (cat)

This patch adds a page-section div around the search results shown by
the call number browser plugin in Cataloging.

The patch also restructures the search form so that the layout is
correct.

To test you must have an item subfield linked to the call number browser
plugin:

- Go to MARC frameworks -> Default MARC framework -> MARC structure.
- Locate the 952 tag and click Actions -> Edit subfields.
- Open the "o" tab and in the last section, "Other options," choose
  "cn_browser.pl" for the plugin field.

Open an item record for editing:

- Go to Cataloging and search for a bibliographic record.
- Click Actions -> Add/Edit items for one of the results.
- In the item edit form, the  "o - Full call number" field should have a
  "..." link at the end.
- Clicking it should trigger a popup window.
- The search form at the top should be laid out correctly.
- Perform a search which will return results.
- The table of results should be contained within a white box.

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>