Bug 28828: Fix unimarc_field_4XX.tt and marc21_linking_section.tt value builders

Bug 28828: Fix unimarc_field_4XX.tt and marc21_linking_section.tt value builders

Find closest ul for value builders.

Since Bug 22399 changes in biblio editor, value builder unimarc_field_4XX.tt JavaScript
code does not do its job anymore.
This is because a div is added and this call is now wrong:
  var subfields = whichfield.parentNode.parentNode.getElementsByTagName('input');

Test plan 1:
1) Use a UNIMARC DB
2) Define value builder unimarc_field_4XX on 463$t
3) Create a record B1 with 200$a, 200$f
4) Create a new record B2
5) Click on value builder in 463$t
6) Search for record B1
7) Click on "Choose"
=> Without patch only 463$t is filled with a value
=> With patch 463 $t, $a, $0 and $9 are filled with a value

Test plan 2:
1) Use a MARC_21 DB
2) Define plugin marc21_linking_section.pl on 773$t
3) Make sure 773$t and other subfields are visible in intranet/editor
4) Create a new record in basic cataloging editor
5) Click on value builder in 773$t
6) Search fro a record
7) Click on "Choose"
=> Without patch fields are not fileld
=> With patch subfields are correctly filled

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>