Woocommerce PayPal Pro 4.5.1

* Fix - Set session cookie if not present while processing payment.
* Fix - Add correct number formatting to AMT in Payflow.
* Fix - Fix rounding issues caused by decimal place store setting and rounding caused by tax calculations.
* Tweak - PHP 8 compatibility.

* Add - SCA support via new 3D Secure 2 setting for modal authentication. (Contact Cardinal to upgrade to Cardinal Cruise before enabling.)
* Update - Cardinal requests to use TransactionType "C".
* Tweak - Omit an additional sensitive Cardinal field from debug logging.
* Fix - Liability shift requirement condition for Mastercard.
* Tweak - WC tested up to 4.0, WP tested up to 5.3.
* Update - Minimum WC version.

* Tweak - WC tested up to 3.7