Replace logic for setting arxiv categories and databases in ArXivDirect.py with a function from ADSCachedExports

[seasidesparrow]

For consistency between Classic and Direct ingest, the code block starting here:

ADSImportPipeline/aip/direct/ArXivDirect.py

Line 123 in 6fc1aff

for keyword in field.split(';'):

should be replaced with a call to this function from adspy.ADSCachedExports:

https://github.com/adsabs/adspy/blob/7372ae93cea32c3dc300cb9ad8493022953bd8f0/ADSCachedExports.py#L1894