Bug 18068: ES - Fix location and (home|holding)branch facets

Bug 18068: ES - Fix location and (home|holding)branch facets

This patch makes the 'Locations' facet work as expected (i.e. having the
same behaviour it has for Zebra: picking the 952$c in MARC21 and 995e
for UNIMARC).

It also adds the code to handle holding and home library settings for
facets and makes the facets show the library name instead of the branch
code.

The mappings are updated so the labels match what facets.inc expect to
work properly.

To test:
- On master, do a search that returns biblios with items having
homebranch set.
=> FAIL: Under the 'Locations' label on the facets you will notice
branchcodes are shown.
- Apply the patch
- Restart memcached and plack (just in case, it was tricky)
- Reset your mappings:
  http://localhost:8081/cgi-bin/koha/admin/searchengine/elasticsearch/mappings.pl?op=reset&i_know_what_i_am_doing=1
- Restart memcached and plack (again, not sure if needed)
- Make sure this mappings are set:
  homebranch => HomeLibrary
  holdingbranch => HoldingLibrary
  (Note: it might not be set due to the place the yaml file is being picked)
- Reindex your records:
  $ sudo koha-shell kohadev
 k$ cd kohaclone
 k$ perl misc/search_tools/rebuild_elastic_search.pl -d -v
- Repeat the initial search
=> SUCCESS: 'Location' contains the right stuff, 'Home libraries' and
'Holding libraries' too.
- Run
 k$ prove t/db_dependent/Koha_SearchEngine_Elasticsearch_Search.t
=> SUCCESS: Tests pass!
- Sign off :-D

Note: play with the 'DisplayLibraryFacets' syspref options.
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>