Make exhibits support the language tagging documented in cocina model

[jacobthill]

The Cocina data model supports parallel fields in multiple languages; here is an example record that is in SDR. We should be able to leverage language tags in cocina to drive language specific tasks in exhibits e.g. language specific Solr configurations, or toggling between languages and seeing the metadata language change. The only fields in exhibits that are setup for languages other than English are the fulltext fields. We will need full support for language tagging for Golistan and other projects. This is a high priority according to our Middle Eastern and South Asian curators.