YITH WooCommerce Points and Rewards Premium 4.3.0

* New: support for WooCommerce 5.3
* Update: YITH plugin framework
* Fix: fixed missing tax in total while removing earned points on order refund
* Fix: fixed issue on calculation in customer history view
* Fix: fixed duplicated messages on cart on update cart totals and on adding to cart from cart page

* New: support for WooCommerce 5.2
* Update: YITH plugin framework
* Fix: managed some filter to correctly change the max discount worth value
* Fix: added class to show the points options on gift card product editing page
* Dev: added filters 'ywpar_reward_message_format', 'ywpar_commission_points_for_affiliate' and 'ywpar_product_points_formatted'

* New: support for WordPress 5.7
* New: support for WooCommerce 5.1
* Update: YITH plugin framework
* Fix: fixed during the order refund
* Fix: fixed issue in threshold message shortcode
* Fix: fixed on discount option in product category
* Fix: fixed points worth calculation
* Dev: added filter 'ywpar_my_account_worth_value'