Index sortable work title field in solr

[mheiman]

Closes #201

Adds title sorting functionality to author and search pages.

Technical

• Modifies managed_schema to:
  • create a new field type, text_title_sortable, that optimizes text for title sorting by trimming white space, lowercasing, and moving initial articles (multi-language) to the end of the string.
  • add a new field, title_sortable of the type text_title_sortable.
• Modifies update_work to populate the new field
• Updates the result sorting interface to use the new field
• Makes the sort field value sticky between searches

The manage_schema type definition includes handling for initial articles from a variety of common languages (English, Spanish, French, German, Italian) but could be expanded to include additional languages.

Source: https://www.loc.gov/marc/bibliographic/bdapndxf.html

Testing

This will require a SOLR reindex to work. After that, the Alphabetical sort option should function correctly on author and search pages.

Stakeholders

@mheiman @cdrini

[cdrini]

Nice! This looks great, @mheiman !

I think the only blocker to merging is making sure we wrap things with if get_solr_next() so that we won't show title sorting option until a full re-index is performed. This is a little annoying, since a lot of the variables aren't available at the right time! It might be easier to add a new variable, title_sort_solr to the openlibrary.yml features section, and then check for that instead.

[cdrini]

Lgtm! Not testing; saw Mark's demo and it looked good! He also confirmed it was working with copyField