The code already knew if the signature was AdES-enabled or not, but that
info wasn't available on the UI.

The values are all names of standards, Andras says it's OK to have them
non-translatable.

Change-Id: I20baf0871fe2c84b04b7fc64014061e341744db8
Reviewed-on: https://gerrit.libreoffice.org/31718Reviewed-by: Miklos Vajna <vmiklos@collabora.co.uk>
Tested-by: Jenkins <ci@libreoffice.org>