Changes in browse/search cultures

- Add 'Unique documents' count to languages facet: shows the number of documents that match the query, no mather in what language they are. When a language is selected it needs a second query without language filter to know the real count.
- Makes ES queries over all available cultures (except autocompletes)
- Change sort field and result values to the selected language facet
- Allows boost options when all culture fields are being set