~ Added: message for function "Buy Course via Product."
~ Fixed: error items cannot be added to LP Order when WC Order is completed by some host without enabling background; will run manually rather than through background.
~ Supported: the shortcode [learn_press_button_course].
~ Fixed: js - with more buttons add to cart on single, archive course.
~ Added: LP Order key on WC order
~ Fixed: error when buy course and product on same order.
~ Added: hook 'learnpress/wc-order/can-purchase-product' for 'Addon coming soon' can rewrite.
~ Fixed: error conflict with addon H5P - not show list product when assign courses to product.
