YITH WooCommerce Subscription Premium 4.4.0

* New: Support for WooCommerce 4.2
* New: Added French translation
* Update: Plugin framework
* Fix: Fixed update shipping address issue

* New: Support for WordPress 5.4
* New: Support for WooCommerce 4.0
* New: Added "Enable Shop Manager" option
* Update: Plugin framework
* Fix: Prevent fatal error if the subscription order is null
* Dev: Added new action 'ywsbs_before_subscription_deleted'
* Dev: Added 'ywsbs_skipped_price_html_filter' filter

* Update: Spanish language
* Fix: Fix undefined index tnx_type
* Fix: Add full log for renew order processing
* Fix: Address fields fix
* Fix: Process_payment function for WC Stripe compatibility
* Fix: Check on cart_item['data']
* Dev: Added filter ywsbs_free_trial_label to change the trial text