YITH Event Tickets for WooCommerce Premium 1.35.0

* New: support for WordPress 5.3
* New: support for WooCommerce 3.8
* New: added new order actions to send processing and completed order emails with event ticket PDF attached
* New: now select service options can be disabled
* New: now tickets can be filtered by Name and Status on backend
* New: now check-in shortcode allows to check-out tickets
* New: added automatic search option for check-in shortcode
* Update: Plugin framework
* Update: Italian language
* Update: Spanish language
* Fix: missing services in CSV export of the tickets
* Dev: added new parameter to yith_start_date_message and yith_end_date_message filters
* Dev: added new parameters to yith_wcevti_allowed_emails filter
* Dev: added ticket price to get_purchased_ticket method
* Dev: added new filter yith_wcevti_add_view_and_gcalendar_button_custom_status
* Dev: added new filter yith_wcevt_args_ticket_purchased_template
* Dev: added new filter yith_check_if_expired_event

* New: WooCommerce 3.7 support
* Tweak: removed call that retrieves all tickets for checkin shortcode (ajax loading will be applied anyway)
* Tweak: add args for service metabox template
* Tweak: check if $item_meta exists
* Tweak: added stripslashes wherever it is required
* Update: internal plugin framework
* Fix: prevent fatal error when not isset $get[post_type]
* Fix: issue with services index, causing new items overwriting previous one
* Fix: fixed barcode value in the CSV export
* Dev: new filters yith_wcevti_load_tickets_purchased and yith_wcevti_search_ticket_output
* Dev: new filter yith_wc_event_tickets_show_already_sold_tickets
* Dev: new action yith_wcevti_order_metabox_end_services

* Update: Added new fonts to mpdf library
* Tweak: Add year range as a parameter
* Dev: Filter yith_wcevt_get_tickets_purchased_by_order_items
* Dev: Filter yith_wcevti_year_range