Add the new collection facet configuration

[jkeck]

Part of #1020 #1034 adds this new field.

A pre-requisite for this issue is to trigger a full-reindex of all the exhibits.

Will we need to identify any data migrations necessary for exhibits that use the current collection facet/field?

[caaster]

Cathy's note: Amy's exhibit is good example https://exhibits.stanford.edu/data. This is about alphabet order of exhibits with multiple collections.