Bug 22596: use raw TT filter in items search with custom field

Bug 22596: use raw TT filter in items search with custom field

When items search is with a custom field using authorised values, html TT filter is breaking the JS, it should use raw.

Test plan :
1) Go to Administration > Item search fields
2) Define a search field with an authorised values category
3) Go to items search
4) Use the "New field" link
5) Check use of custom field is OK

Signed-off-by: Liz Rea <wizzyrea@gmail.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>