Fixed edan_to_dpla.transform_date exception for non-iterable dates

Added handling for when arc_group_extraction() returns None, which
is not iterable by the ensuing for loop.  Assuming that returning
{} is OK because that was already possible under another
circumstance.
Added determination of Smithsonian type for physical format (#4265)

Updated akamod.edan_to_dpla
Added configuration to specify type lookups
Updated and added edan_to_dpla tests
Updated version and other info in setup.py
Merge branch 'release-v19.1'

- Added determination of Smithsonian type for physical format (#4265)
- Fixed edan_to_dpla.transform_date exception for non-iterable dates