Add a new option on combined campaigns => "Exclude"

We run up to 100 campaigns in parallell. Sometimes the same products are involved in different campaigns but we only get kickback for one campaign on each order. That means we need to block those campaign to be combined, while it's perfectly fine to combine different campaign where the products don't overlap. Since we have so many campains running at the same time it's not possible to maintain a list of allowed campaign to be combined. We wish there would be an option to instead EXCLUDE a certain combination.