Search formats should display in advanced search filter block on search results page

[Kathy Lussier]

Evergreen version 2.12

With the new 2.12 advanced filter block that displays on the search results page, we remove several filters that shouldn't display here, primarily because they are already available in the search bar.

In commit f12cc28, we added code to ignore the search format filter. While this choice makes sense on a stock system where the search formats are only available from the search bar, there are several sites that also provide the search formats as a limiter on the advanced search results page, primarily because these filters are more user friendly than the item type, item form, bib level limiters.

Since users can choose multiple search formats from the advanced search page, we really need to display those formats in the advanced filter block along with other filters. There are two pieces to this bug (or, perhaps, two distinct bugs).

1. We need to not ignore the search format filters when the search originates on the advanced search page.

2. I've configured my system locally to not ignore those filters, but a new problem arises. Let's say the user limits the search to CD Music Recording and Music Score. On the advanced search page, those two filters will display in the block as the other filters do, but one of those filters (Music Score) also displays in the format selector on the search bar. If a user conducts a new search for the search bar, the Music Score format filter is applied twice. Ideally, the system would be smart enough not to add the second filter.

[Kathy Lussier (klussier)]

Adding link to related bug 1679309.