Event Tickets: Limit ticket purchase / RSVP#17

Requesting the ability to cap how many tickets/RSVPs a single buyer or organization can purchase for an event. Shipped via the new Purchase Rules feature. (Migrated from featureOS: https://the-events-calendar.featureos.app/p/event-tickets-limit-ticket-purchase-rsvp-b1257c0d-3ccd-43ba-b479-c7aefaa97772)