Go back to LocalDateTime.

Finally fix an error in the conversion from DBObject to DataEntry.
:japanese_goblin:
Return a response with a list of DataEntry.

Use
GenericEntity<List<DataEntry>> entityResultsInDataEntry =
new GenericEntity<List<DataEntry>>(queryResults) {};
to preserve the objects in the list.

I still don't know if is this what I really want but was
a matter of principle.
Verbose test, but...

I still have the bug with the GenericType entity list that eats the
date.