showing whether the signature behind the signature line is valid or not.

Change-Id: Ia6cca62812019f26d55d234cac767a9b4b7c8175
Reviewed-on: https://gerrit.libreoffice.org/40980Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Samuel Mehrbrodt <Samuel.Mehrbrodt@cib.de>