The capture and display filter widgets set their dropdown arrow icons
using CSS, which means we can't use a template icon without a
significant amount of hackery. This is the only instance where we set an
icon using CSS, so split it into dark and light versions and use them as
appropriate.
Ping-Bug: 15511
Change-Id: I699ddc327d8eb109129e60bcb5036b14e6e34414
Reviewed-on: https://code.wireshark.org/review/33696
Reviewed-by: Gerald Combs <gerald@wireshark.org>
Petri-Dish: Gerald Combs <gerald@wireshark.org>
Tested-by: Petri Dish Buildbot
Reviewed-by: Alexis La Goutte <alexis.lagoutte@gmail.com>