Add customer actions hook and appointment creation functionality

- Implement customer ID assignment in the appointment creation process.
- Create a new partial for customer actions to render appointment links.
- Add localization for the "Add Appointment" label.
- Introduce CustomerActionsHookListener to manage customer actions rendering.

lib/redmine_qbo_calendar.rb

@@ -17,5 +17,6 @@ module RedmineQboCalendar
 
     # Hooks
     RedmineQboCalendar::Hooks::ViewHookListener
+    RedmineQboCalendar::Hooks::CustomerActionsHookListener
   end
 end