The Events Calendar - Event Tickets Plus 5.10.1

* Feature - Placeholder support added for Text, Email, Telephone and URL Attendee Registration Fields. [ETP-711]
* Fix - The Attendee Registration modal cart, now makes the right calculation when removing items. [ETP-715]
* Fix - Show total attendance count for `tribe_attendee_list` shortcode title. [ETP-129]
* Tweak - Add Attendee Registration Fields to the Tickets editor UI for the classic editor. [ETP-594]
* Tweak - Add new filter to allow filtering of the QR Code check-in API key. [ETP-720]
* Tweak - Added filters: `tribe_tickets_modal_show_if_no_ticket_with_ar_in_cart`, `tribe_tickets_plus_manual_attendees_view_send_ticket_email_for_new_attendees`, `event_tickets_plus_placeholder_enabled_ar_fields`, `event_tickets_plus_requested_api_is_valid`
* Tweak - Changed views: `meta/email`, `meta/telephone`, `meta/text`, `meta/url`, `v2/attendee-registration/mini-cart`
* Language - 3 new strings added, 17 updated, 0 fuzzied, and 0 obsoleted

* Tweak - Handle changes on the attendee meta fieldset styles when Individual Attendee Collection is enabled. [ETP-699]
* Tweak - Added filters: `tribe_tickets_modal_show_if_no_ticket_with_ar_in_cart`, `tribe_tickets_plus_manual_attendees_view_send_ticket_email_for_new_attendees`
* Tweak - Changed views: `v2/attendee-registration/mini-cart`
* Language - 1 new strings added, 5 updated, 0 fuzzied, and 1 obsoleted

* Fix - Resolve PHP notices when creating new tickets with Attendee Registration Information. [ETP-713]