fix: add Injectable decorator to MatchMapStatusEvent for proper DI

[Flegma]

Summary

• Add missing @Injectable({ scope: Scope.REQUEST }) decorator to MatchMapStatusEvent
• Without the decorator on the child class, NestJS falls back to the parent's constructor metadata (4 params), so the 5th parameter (NotificationsService) is never injected
• This caused this.notifications to be undefined at runtime, crashing with TypeError: Cannot read properties of undefined (reading 'sendMatchMapPauseNotification') when a match map enters the "Paused" status, preventing matches from starting/progressing

Test plan

• Verify matches can start and progress through map statuses without errors
• Verify pausing a match map triggers the pause notification without crashing
• Verify no regression in other match event processors

[lukepolo]

so this will also cause moe memory usage, we might want to just add notification service on to the parent class. the request scope means each time it comes into will generate the notification service (new) each time.

[lukepolo]

TLDR; just add the notification service to the parent