Test using nested fields to store project specific info

[karindalziel]

If dynamic subfields could be added, we could have a single "miscellaneous" field (probably need a better name) and then use that to store extra info.

For instance, for African poetics citations, we need fields like "Source Access Date, Source Archive, Source Citation"

-misc
- citation_source_access_date
- citation_source_archive
- citation_source_full_citation

This is perhaps not the best example but the first step is to make sure we can create dynamic subfields at all.

[jduss4]

dynamic subfields can be added. i would still prefer not to get too wild with these, and to consider how other projects might be able to use the same ones (like petitioner_against_k type fields. Also, our API querying structure does not currently support nested-nested fields, for example:

miscellaneous:
  {
    citation_n:
      {
        citation_source_access_date_k: ""
      }
  }