Create a single facet that includes all values of /mods/name/namePart

[caaster]

Story: Exhibit curators would like to simplify display and access by being able to include all creators, regardless of type or role, in the same facet field.

Acceptance criteria: A single facet field should be available that includes all values of the /mods/name/namePart element, in addition to the current creator facets.

Fixture objects in #889

[cbeer]

How do we know if a mods:name is a "creator"?

[arcadiafalcone]

I'm inclined towards doing away with the creator/contributor distinction altogether for MODS, since it's not a division in the standard itself. Current practice is biblio-centric in limiting creatorship to "author" or generic "creator", which doesn't work when the creator's role is properly defined as composer, director, interviewee, performer, architect, cartographer, etc. depending on what is appropriate for the format.