Repair faulty MARC editor authority validation

Repair how the JS inspects the results of
open-ils.search.authority.simple_heading.from_xml.batch.atomic, which is
used to look up matches for authority validation.  It returns a more
complex structure in the brave new world of authority control sets.

Signed-off-by: Bill Erickson <berick@esilibrary.com>
Signed-off-by: Mike Rylander <mrylander@gmail.com>
Correct subfield format for authority lookup

The Authority Control Set code expects the format of subfields
that it will be used to build a MARC.Field object to be of the
form: [[code,value],...]  This commit makes that true.

Additionally, dojo.filter over a list of lists can cause the
nested array set to be flattened.  So, instead, we loop directly.

Signed-off-by: Mike Rylander <mrylander@gmail.com>