YITH WooCommerce Membership Premium 2.20.0

New: support for WordPress 5.8
New: support for WooCommerce 5.5
Update: YITH plugin framework
Update: language files
Fix: credits taking into account paused days
Tweak: localized 'Next Credits Update' date in Membership details
Tweak: fixed issue when calculating the remaining days

* New: support for WooCommerce 5.3
* Update: YITH plugin framework
* Update: language files
* Fix: up-sell product visibility if any of them is included in a membership plan
* Fix: notice shown in 'recent posts' widget
* Fix: filtering allowed posts in queries when the post_type is not directly set, so it'll be 'post' by default
* Dev: applied yith_wcmbs_membership_restricted_post_types in membership-plans template

* New: support for WooCommerce 5.0
* Update: YITH plugin framework
* Update: language files
* Fix: issue with membership shipping conditions for guest users
* Fix: issue when using 'embed' shortcode in alternative contents
* Dev: added yith_wcmbs_admin_membership_info_expiration_date filter