YITH WooCommerce Ajax Product Filter Premium 5.9.0

* Fix: Unable to reset filter in subcategory page
* Dev: yith_wcan_display_type_select hook
* Dev: yith_wcan_select_type_query_arg hook
* Dev: yith_wcan_select_type_current_widget_check hook
* Dev: yith_wcan_select_filter_operator hook

* New: Support to WooCommerce 3.6
* Update: Plugin Core Framework
* Fix: undefined variable term_id in attributes table

* Fix: Wrong reset page with WooCommerce Filter by price widget
* Fix: Support to Aurum theme - Filter issue using AND operator
* Update: Plugin Core Framework
* Update: All language files (Italian, Dutch and Spanish)
* Tweak: New Widgets name
* Dev: yith_wcan_unfiltered_args hook to manage the unfiltered args for get_posts
* Dev: yith_wcan_skip_no_product_count_bicolor hook to skip show bicolor wit no products