Create profile for UVA book data

- Refactor mods_to_dpla
Fix SCDL format issues

- Fix "Pamplets" and "black-and-white photographs"
- Update SCDL pluralize dict in the lookup module
Fix Harvard and NARA index errors
Various fixes

- Use production URL for David Rumsey
- Fix ArtStor thumbnail parsing
- Fix DLG thumbnail parsing
- Do not save documents that are missing sourceResource
- Updated AstStor tests
Merge branch 'release-v4.0'