WP-Lister Pro for eBay 3.8

* New: Record Buyer VAT ID if provided by eBay
* New: Support for updating product-level Item Specifics using the REST API (beta)
* Tweak: Add links to the Duplicate Listings report table
* Tweak: Moved the provider value of the Shipment Tracking metadata to the custom_tracking_provider property
* Tweak: Change the context when fetching the order tracking information from view to edit to bypass the cache
* Tweak: Added a fallback method with file_put_contents fail when saving templates
* Fix: Changed calls triggered by the plugins_loaded to the init event to prevent getting the _load_textdomain_just_in_time warning
* Fix: Cannot access offset of type string on string
* Fix: Title prefix and suffix for split variations are still pulled from the parent product
* Fix: Mapped categories not getting loaded for new/unlisted products
* Fix: Warning when trying to access HazMat Statements
* Fix: Include variation price in the request when deleting listing on eBay
* Fix: Error when the WPL_WooOrderBuilder::updateShippingTotal() is NaN
* Dev: Scope warning of the WPL_Model::handle_error_code property
* Dev: New filter `wple_listings_search_description`
* Dev: Changed the priority of handle_woocommerce_order_status_update to allow shipment tracking plugins to store the tracking data first
* Dev: Commented out the action_scheduler_queue_runner_time_limit add_filter call which could be causing stalled actions in Action Scheduler
* Dev: Increased the column length for the ShippingAddress_City

* Hotfix: `Call to a member function get_id()` breaking order imports

* Fix: Use wp_remote_fopen() to get around allow_url_fopen restriction
* Fix: Check the input URL before including it in the request to add or revise eBay listings
* Dev: Display Pro features in WP-Lister Lite