New set of gradients incl. l10n and ui test

Change-Id: Iee303a39ad721b5a4e8b9adb78ee5a82227b84f4
Reviewed-on: https://gerrit.libreoffice.org/53934Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: andreas_kainz <kainz.a@gmail.com>