YITH WooCommerce MailChimp Premium 2.34.0

* New: support for WooCommerce 3.9
* New: added support for address type fields at checkout
* Update: plugin framework

* New: support for WordPress 5.3
* New: support for WooCommerce 3.8
* Tweak: delete store transients when deleting store, even if API call fails
* Tweak: avoid using SELECT *
* Update: Plugin framework
* Fix: preventing fatal error when it is not possibile to retrieve product object from order item
* Fix: improved check on campaign data before sending a registered order to MailChimp
* Fix: changed hook to avoid ajax call and duplicate checkbox on checkout page
* Fix: issue with persistent cart (undefined index line_total | line_subtotal)

* New: WooCommerce 3.7.0 RC2 support
* New: integration with Checkout Manager field
* Tweak: now carts are registered even if customer does not have a billing email
* Update: Italian language
* Updated dutch language
* Fix: subscribe interests groups in the shortcode
* Fix: issue with custom option saving & printing on WC panels with WC 3.7
* Dev: new action yith_wcmc_register_customer_subscribed_list
* Dev: new action yith_wcmc_user_subscribed_in_form_subscribe
* Dev: new param to action yith_wcmc_user_subscribed_in_form_subscribe
* Dev: new added 'yith_wcmc_get_checkout_fields' filter.