LP#1831784: fix Angular's formatting of DOB field

LP#1831784: fix Angular's formatting of DOB field

Otherwise, depending on the local time zone, the date displayed
could be off a day.

The 'dob' columns are currently the the _only_ database/IDL fields
that are truly dates, not timestamps, hence the hard-coded exception.
However, an alternative approach would be to define a new 'date'
field type in the IDL.

To test
-------
[1] Construct an eg-grid (say, on the Angular sandbox page) that retrieves
    patron records. For users in North America, the birth dates are
    likely off by a day.
[2] Apply the patch and repeat step 1. This time, the birth dates should
    display as entered.

Sponsored-by: MassLNC
Sponsored-by: Georgia Public Library Service
Sponsored-by: Indiana State Library
Sponsored-by: CW MARS
Sponsored-by: King County Library System
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>
Signed-off-by: Bill Erickson <berickxx@gmail.com>
Signed-off-by: Galen Charlton <gmc@equinoxinitiative.org>