feat: Display ticket based on `qr_code` field

- Previously ticket was displayed using id which is too easy to find
- Now the URL takes ``qr_code`` field as parameters

app/controllers/tickets_controller.rb

@@ -48,11 +48,10 @@ class TicketsController < ApplicationController
     end
   end
 
+  # Display informations about the event with QR code
   def show
-    @ticket = Ticket.joins(order: :user).includes(:event, :ticket_type, order: :user).find_by(
-      tickets: { id: params[:ticket_id] },
-      orders: { user_id: current_user.id }
-    )
+    @ticket = Ticket.joins(order: :user).includes(:event, :ticket_type, order: :user)
+      .find_by(tickets: { qr_code: params[:qr_code] })
 
     if @ticket.nil?
       redirect_to dashboard_path, alert: "Billet non trouvé"
@@ -63,6 +62,7 @@ class TicketsController < ApplicationController
   rescue ActiveRecord::RecordNotFound
     redirect_to dashboard_path, alert: "Billet non trouvé"
   end
+
   private
 
   def set_event