WooCommerce PDF Product Vouchers 3.12.3

* Fix - Activate a voided voucher when an order is completed
* Fix - Redeem single-purpose vouchers (SPV) in multiple failed use cases

* Feature - Add QR & Barcodes to vouchers and scan them easily from the admin for quick voucher redemption
* Dev - Namespace the SkyVerge Plugin Framework and move to the /vendor directory
* Localization - Added Italian translation

* Fix - Address rounding issues on redemptions for stores using tax inclusive pricing
* Fix - Generate second page when additional image is added
* Misc - Add support for WooCommerce 3.5