Right now our IQE tests use SavingsPlanCoveredUsage in a few generators but these do not include Negation line items as koku expects (limitation in Nise, see COST-5378)

IQE tests need to be updated to assert the new corrected values. Essentially any line item that has a cost type of `SavingsPlanCoveredUsage` should = 0 cost Because they SHOULD include the exact amount of negative cost from `SavingsPlanNegation`.