Bug 31841: Use location,wrdl when searching Shelving location

Bug 31841: Use location,wrdl when searching Shelving location

The "location" index only has a word index defined, so we need
to specify the wrdl qualifier when searching it via the staff
interface dropdown menu

Test plan:
1) Change QueryAutoTruncate to "only if * is added"
2) Change IntranetCatalogSearchPulldown to "Show"
3) Search for "Shelving location" of "GEN" in catalogue
search bar
4) Note no results returned

5) Apply patch
6) koha-plack --restart kohadev

7) Repeat Step #3
8) Note that results appear for 'location,wrdl: GEN'

Signed-off-by: Magnus Enger <magnus@libriotech.no>
Works as advertised.
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>