YITH WooCommerce Ajax Product Filter Premium 5.5.0

* New: support for WooCommerce 9.3
* Update: YITH plugin framework
* Tweak: filter terms count even if no layared nav is applied
* Fix: return value for render method of yith_wcan_filters shortcode in case of error

* New: support for WooCommerce 8.9
* Update: YITH plugin framework
* Tweak: use specialized option for Variations filtering
* Tweak: changed cache system, to store fewer final results instead of heavier data still to be processed
* Tweak: stop caching variations filtering query result (high impact on db)
* Tweak: added cache for single variation id matching query
* Tweak: improved row meta handling
* Tweak: minor style changes to the admin panel
* Fix: improved handling of filterId and filterKey at backend, to avoid possible filters duplication/overriding when saving via AJAX
* Fix: prevent filters lazy loading when doing shortcode preview in Gutenberg
* Fix: problem with terms hierarchy when ancestor is not included among selected filters
* Fix: prevent terms pagination when returning 0 as terms_per_page
* Fix: wait 300ms before filtering after price slider action
* Fix: prevent horizontal toggle closing when clicking inside the toggle
* Fix: js error with MapIterators on FireFox
* Fix: terms selection field not working for new filters in Preset edit page
* Fix: term box not appearing in Preset edit page when selecting first term in search box
* Fix: restored correct behaviour for filters applied in YITH_WCAN_Query::get_query_relevant* methods (filter product ids instead of counts)
* Dev: added new yith_wcan_filter_open_button_class filter

* New: variations filtering - only show variable product if at least one variation matches current filter selection
* New: variations filtering - when only one variation matches current filter selection, change variable product layout to represent matching variation
* New: option to lazy load filters into the page via AJAX
* New: option to paginate terms, loading second page via AJAX
* New: support for WooCommerce 8.8
* New: term boxes are now paginated on Preset edit page, to avoid excessive JS processing on page loading
* Update: YITH plugin framework
* Tweak: major code refactoring
* Tweak: improved overall performance of Preset edit page, improved saving process
* Fix: error with closing toggle dropdown immediately after the filter is selected in horizontal mode
* Dev: added yith_wcan_query_relevant_term_objects filter
* Dev: added yith_wcan_query_relevant_on_sale_products filter
* Dev: added yith_wcan_query_relevant_in_stock_products filter
* Dev: added yith_wcan_query_relevant_featured_products filter
* Dev: added yith_wcan_query_relevant_rated_products filter
* Dev: added yith_wcan_query_relevant_price_range_products filter
* Dev: added yith_wcan_query_relevant_min_price filter
* Dev: added yith_wcan_query_relevant_max_price filter