The current Breeze splash screen is rather visually incongruous with what comes
immediately before and after it by default: before it is the login screen which
displays a blurred version of the current Next wallpaper by default, and after it
is the desktop, which, again, by default displays the current Next wallpaper.
This patch makes the Breeze theme splash screen use the same wallpaper, which
looks much better.
[RFC] because we should really use some CMake variables to build the first part of
the path like we do for the SDDM theme's config file. I couldn't figure out how to
do this though and need a little help.