[-] CORE : static cache bugfix 

Bugfix for static cache bug referenced in PR 2205.

Cart->getGiftWrappingPrice()
Cart->getNbOfPackages()
Cart->getDeliveryOptionList()
Cart->simulateCarriersOutput() <- $cache unused here
Cart->isMultiAddressDelivery()

Probably that this code must be tested to be sure it does not add any regression or bug on impacted features