Support LC Resource Types Scheme as well as deprecated MODS typeOfResource vocabulary

[arcadiafalcone]

Previously MODS defined a set of valid terms for typeOfResource. In MODS 3.7 that changed, and best practice is now to use the LC Resource Types Scheme instead. Some metadata in SDR already uses the term "Dataset" from this schema. In particular format_main_ssim is very dependent on this field. The indexing logic should be updated to support terms from both schemas.

LC Resource Types Scheme: https://id.loc.gov/vocabulary/resourceTypes.html