Don't make separate request for every publish in search/publishers

[cdrini]

Closes #7712

Technical

• Limit to searching for type: work ; we don't want to search editions here. This should also be a speed improvement!
• Both the original implementation and the new implementation have slight bugs
  • Original: Would return publishers which didn't match the query. For example, searching for New York would return Springer, because a facet search finds all publishers for the query. And some books with publisher:New York also have publisher:Springer, causing it to return Springer as a match. Fixed in current by adding the facet.contains solr parameter to reduce the result set, but note this is strict, so it won't do any stemming/etc like the original search.
  • Current: The counts could be slightly off, but it's rather unlikely.
  • Current: The search is now doing a more literal substring search to appease facet.contains, but this is better than the previous approach which was returning irrelevant results.

Testing

Screenshot

Before:

After:

Stakeholders