Complete tickets reminder

[techenby]

This PR adds a scheduled complete tickets reminder command. This command will remind all orders for future events that they have incomplete tickets (either unassigned or pending invitation).

In addition a dev routes file was added so this notification can be previewed locally.

Preview of notification

[what-the-diff[bot]]

PR Summary

• Introduction of Ticket Completion Reminder A new feature has been developed that sends email reminders about incomplete tickets in an order. It has been encapsulated into a command named CompleteTicketsReminder.

• Incorporation into the System's Schedule The CompleteTicketsReminder command has been included in the system's schedule to automatically run every Monday, ensuring regular check on ticket completion.

• Generation of Notifications This PR introduces a notification class CompleteTicketsReminder which is responsible for sending out the actual email reminders regarding incomplete orders.

• Cleaning of Unused Methods The file app/Notifications/PaymentReminder.php has been optimized by removing unused methods.

• Inclusion of Direct Route to Trigger A user-friendly route has been added in routes/dev.php. It can trigger the CompleteTicketsReminder notification for an order directly from the web url.

• Extensive Testing Comprehensive tests have been established to verify the correct behavior of this new feature. They confirm that email reminders are sent for orders with incomplete tickets and exclude the orders of past events from such reminders.