insert "(blank)" when facet is empty
Issue
This experiment replaces a blank facet value with "(blank)", e.g.,
Problem
While this now makes that blank facet value clickable, it does not do what you expect, e.g.,
http://localhost:3004/records?f%5Bcreator_facet%5D%5B%5D=&only_path=true
(note that the facet value is empty).
The above link will display ALL records (with the creator facet expanded), whereas the user probably expects to display the two records with no creators.