Introduce QCryptoBlock-based functions and use them where possible.
This is needed to implement thread-safe encrypt/decrypt operations.
Signed-off-by: NVladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: NAlberto Garcia <berto@igalia.com>
Signed-off-by: NDaniel P. Berrangé <berrange@redhat.com>