YITH WooCommerce Ajax Product Filter Premium 5.9.0

* New: Support for WordPres 5.0
* Tweak: Option description
* Fix: Undefined index: source_tax in YITH Reset Filter widget
* Fix: Issue with reset filter in product categories page
* Dev: new parameter for filter 'yith_wcan_dropdown_label'

Update Plugin core framework
Tweak Replace the old function remove_premium_query_arg with the new one yith_remove_premium_query_arg
Fix Reset button doesn't works if a variable use a slash char in query string
Dev New filter yith_wcan_term_name_to_show

* New: Support for WooCommerce 3.5
* New: Option to add rel="nofollow" to filter links
* New: Support for Aardvark theme
* New: Support for Aurum theme
* New: Support for UX Shop theme
* New: Support for YooTheme theme
* Fix: Wrong results with search query string
* Fix: Double chosen icon with themes that override layered navigation style
* Fix: Ghost query arg when try to deactivate category filter
* Tweak: Widget reinit after ajax call
* Tweak: Flatsome optimization
* Tweak: Prevent untrailingslashit on filter url for SEO optimization
* Update: Spanish language
* Update: Italian Language
* Dev: yith_wcan_skip_no_products_label hook