tdf#100015 Move unary and binary operators icons to Galaxy

These are help-only anyways. Also they were on a path
that was not auto-packaged into images_elementary.zip
this is fixed as well.

Change-Id: If102bcc70c2cf22eee3c9513ebdda38a634b1f54
Reviewed-on: https://gerrit.libreoffice.org/30375Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Andras Timar <andras.timar@collabora.com>