Fetching shipping address, Wrong watchdog exception, SkipReview error

Problem/Motivation

1. When you go from cart to the checkout a fatal error occurs due to $this->order->get('payment_gateway') being null
2. When checking to fetch the shipping address from Sezzle it adds an additional step on Sezzle, but does not append to the Commerce order
3. mapAndCreateSezzleOrder method watchdog_exception() throws error: wrong parameter sent to the
4. $this->entityId is deprecated
5. Change unique order identifier sent to sezzle from order id to order uuid. This was changed because when having multiple enviroment and you are testing the payment will fail

Proposed resolution

Patch attached fixes all of the issues