Where it can be done by removing useless / duplicate code.
For XFListStyle I removed the copy operator entirely, because it
was bugous and it seems not to be used anyway.

Change-Id: Iba0eb0d5c45b42f0e78be466c617acdc1216eb22
Reviewed-on: https://gerrit.libreoffice.org/70482Reviewed-by: Tamás Zolnai <tamas.zolnai@collabora.com>
Tested-by: Tamás Zolnai <tamas.zolnai@collabora.com>