packaging: setup: allow interactive PKI cleanup

allow interactive PKI cleanup with engine-cleanup-2

- cleanup PKI configuration and keys only if requested
- backup PKI configuration and keys it cleanup requested

Change-Id: Ib6efe201ed5a9dee7f681ffd61c8f988d24a33a7
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>