Refactor collection_with_title field to not include the druid

[jkeck]

We don't make use of the druid part of this field and have to provide helper methods handle the field parsing. Since we own our own indexing logic completely now, we don't need to have this compound field (which is a holdover from the SearchWorks indexing pipeline).

[jkeck]

This is going to have to wait until 1.14.0 to be resolved. We have a new field in the indexing code for this field in 1.13.0, but we'll need to re-index all documents to populate the data before we surface the field as a new facet (and hide the previous one).

[corylown]

The "new" field collection_titles_ssim exists for most indexed items, but the following exhibits still have documents indexed that have collection_with_title but lack collection_titles_ssim:

• data
• exemplars
• harrison
• alcoa
• stanford-senate
• oral-history
• preventing-genocide
• women-art-revolution
• stanford-band
• su-photos
• hanna-house-collection
• menuez
• gatt
• digital-bookplates
• memorialchurch
• ua-maps-drawings
• women
• ""
• my-favorite-cats
• kzsu
• community
• tel-aviv
• news-service
• time-travel-japan
• views-portraying-place-space
• stanford-stories
• lanciani
• maps-of-africa
• stanford-pubs
• stanfords
• ruderman
• renaissance-exploration
• gordon-maps
• mss
• rare-music
• chinese-ngos
• heckrotte
• bach-test
• kolb
• activism
• queer
• cs
• feigenbaum
• ai
• h2-test

The items in these collections would need to be reindexed to pick up the collection_titles_ssim field. The items still missing this data can be found with the following solr query: exhibits-prod/query?q=*:*&q.op=OR&indent=true&fl=spotlight_exhibit_slugs_ssim&rows=11000&wt=csv&fq=collection_with_title:*&fq=-collection_titles_ssim:*

I think the goal for this is to stop using the collection_with_title for display and facets since these both rely on helper methods collection_title and document_collection_title to strip the druid from the data stored in solr. We should remove the helper methods once this is complete.