Change  introduced a conditional call to Field's
"adapter" callable supposedly to work-around some OEM issues.
Sadly, the exact problem that change  has been trying to
solve was never explained and remains murky.
However, fix  has also introduced a bug which makes sushy
ignoring 'None' literals in the values. This sometimes leads
to sushy failing to operate on perfectly valid JSON documents.
This change removes most of the conditions guarding Field's
"adapter" function calls.