* Fix - Dev - Fix unit testing infrastructure and make it compatible with PHP 8.
* Fix - Fix the JS error when displaying the booking detail in Calendar > Day view.
* Fix - Register menu items with WC Navigation.
* Fix - WC no longer uses SemVer, so update to support L-2 version of WC.
* Tweak - WC 5.0 compatibility.
* Tweak - WP 5.6 compatibility.