YITH WooCommerce Account Funds Premium 1.35.0

* New: Support for WooCommerce 4.0
* New: Support for WordPress 5.4
* Update: Plugin Framework
* Update: Greek language
* Update: Spanish language

* New: Support for WooCommerce 3.9
* Update: Language files
* Dev: Add new filter yith_funds_coupon_data
* Dev: Add new filter ywf_enable_discount

* New: Support for YITH WooCommerce MultiVendor Premium 3.5.0
* New: Vendor's commission can be paid with funds
* New: Support for WooCommerce 3.8
* New: Support for WordPress 5.3
* New: New plugin panel style
* New: Greek language file
* Tweak: Partial Payment system
* Update: Italian language
* Update: Spanish language
* Update: Plugin Framework