* Tweak-WC 5.0 compatibility.
* Tweak-WP 5.6 compatibility.

* Fix: issue with plain text emails not displaying as expected
* Fix: fatal error with events plugin add-on ‘Enhance Woo Order Templates’
* Fix: removed waitlist notice from product page if it was empty
* Fix: php8 deprecation notice fix
* Fix: events ticket class checks updated as new classes have been added/changed (checkbox HTML)
* Added: action hooks before and after waitlist mailout process
* Added: filter to customise when mailout should be processed
* Added: user flag for guests in admin panel row
* Added: include wcwl prefix to ticket variable names to avoid potential conflicts

* Fix-Possible conflict with Advanced Shipping Packages.

* Tweak-WC 5.0 compatibility.
* Tweak-WP 5.6 compatibility.