Amazon Fulfillment (MCF) for WooCommerce 4.2.8

* Fix: Send city if no zip code is available when calculating shipping cost
* New: Added filter ns_fba_fulfilment_shipping_title to allow changing the shipping title.

• Fulfiment by variation. New checkbox to allow selecting of which variations to fulfil.
• improvements.

* Fix: Do not send products without an SKU. This is to prevent errors in submission
* Fix: Check status response of orders sent to fulfilment to prevent marking orders as sent when it failed.

* Bug fixes

* Fix issues with manually sent orders in the admin for products not meant to fulfil with Amazon

* Tracking code fixes and order checks
* Better logging

* Connection url updates.
* Code fixes and improvements.

* PHP 7 compatibility fix.
* Other code fixes and improvements.

* Add integration with Shipment Tracking plugin.
* Only show tracking order notes once when syncing the order status.

Fix order sync tracking details.