Fix USE_CONFIG_APPROVE_CONFIRMATION and USE_CONFIG_REJECT_CONFIRMATION

Fix USE_CONFIG_APPROVE_CONFIRMATION and USE_CONFIG_REJECT_CONFIRMATION

They still showed UI in case of signed macros.
Two decisions were made, to improve security of USE_CONFIG_APPROVE_CONFIRMATION:
1. In case of High macro security mode, valid but untrusted certificate will be
   automatically rejected (because it is not safe to automatically add trusted
   certificates) - so in this mode, USE_CONFIG_APPROVE_CONFIRMATION is the same
   as USE_CONFIG_REJECT_CONFIRMATION;
2. In case of Medium macro security mode, valid but untrusted certificate will
   not automatically allow macros execution, but will proceed to the following
   checks - which on Windows will try to check the source's Security Zone, and
   may disallow macros based on that. Only after Security Zone check the macros
   will be automatically allowed.

Change-Id: I1a9c92c6b940b689599c5d106798ecfc691dad46
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/159214
Tested-by: Jenkins
Reviewed-by: Mike Kaganski <mike.kaganski@collabora.com>
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/159278
Reviewed-by: Miklos Vajna <vmiklos@collabora.com>