Decryption key:
* Fix - Resolved two issues preventing the correct display of the "Subscription items can no longer be edited." message on the Edit Subscription page.
* Fix - Checks for the existence of `wc_get_page_screen_id` before calling it on `wcs_get_page_screen_id`, and for the admin context before calling `list_table_primary_column` to prevent fatal errors.
* Fix - Blocks the reactivation of a subscription when the end date is in the past.
* Fix - Ensure a subscription's modified date is updated when its related order cache is updated on non-HPOS sites.
* Fix - Ensure trial period form data is set before use to prevent fatal errors when the data is missing.