Bug 7501: OPAC auth browser should have alternating colors

Bug 7501: OPAC auth browser should have alternating colors

Test plan:

1. Access authority browser in OPAC. Note that all rows have the same background
   color.
2. Apply patch, notice that colors now alternate.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>
(cherry picked from commit 44fd379dc23fb4423619ab07e5f4a4906c097a6c)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>
(cherry picked from commit 4b1f2c01a12fac9b46f3c140901f1d8003276535)

Signed-off-by: Chris Nighswonger <chris.nighswonger@gmail.com>