Different approach for zone outage scenario implementation

[agabriel81]

Adds a new feature in the zone scenario where the AWS deny-all network ACL is already created by the customer and the kraken zone outage scenario will only assign / replace the deny-all network ACL and revert back to the original AWS network ACL at the end of the scenario.
So, for example, having a configuration like this one:

  zone-outage:
    cloud-type: aws
    duration: 50
    vpc-id: vpc-085cf4c0a30d56b2d
    subnet-id: subnet-0c858b2ac477e4489
    nacl-id: XXX-1234asdf-XXX
    region: eu-central-1

it will assign the customer pre-created deny-all network ACL with ID XXX-1234asdf-XXX to the subnet subnet-0c858b2ac477e4489 and revert back to the original network ACL.