WooCommerce Waitlist 2.4.9

* Fix: updated archive validation
* Fix: add user to archive not working if archives not returning as array

* Fix: fixed issue where waitlist counts were showing as 1 by default when updated
* Fix: made settings text translatable
* Fix: fixed bug where updating waitlist counts when no products exist
* Fix: updated order->user_id to use new format order->get_user_id()
* Added in setting to update waitlist counts manually
* Added support for multiple parent products (grouped products)
* Added product ID to filter for disabling persistent waitlists
* Added product ID to filter for disabling automatic mailouts
* Removed auto updates of waitlist counts to avoid issues with large product databases

* Fix: Adjusted mailouts for variable products so the parent variable can control mailouts for child variations if managing stock
* Fix: Adjusted how grouped products are handled to avoid waitlist adjustments on page reloads
* Fix: Added appropriate message for logged out users when registration is required