Check for a column that has "issn" or "isbn" in the name rather
than by its explicit name, as the column is dc.identifier.issn now,
but will be cg.issn in the future if CG Core v2 happens.
I'm only concerned with validating issue dates here. In DSpace they
are generally always YYYY, YYY-MM, or YYYY-MM-DD (though in theory
they could be any valid ISO8601 format).
This also checks for cases where the date is missing and where the
metadata has specified multiple dates like "1990||1991", as this is
valid, but there is no practical value for it in our system.