register all cron jobs in entrypoint (#12791)

closes https://github.com/twentyhq/core-team-issues/issues/1113

Three things I am not sure about - 
- Should we have a variable just like DISABLE_DB_MIGRATIONS to control
cron job registration behavior, i.e., DISABLE_CRON_JOBS_REGISTRATION?
- The location of the command ie, folder placement
- https://github.com/twentyhq/twenty/pull/12791/files#r2161734131

packages/twenty-server/src/modules/calendar/calendar-event-import-manager/calendar-event-import-manager.module.ts

@@ -67,6 +67,12 @@ import { RefreshTokensManagerModule } from 'src/modules/connected-account/refres
     CalendarOngoingStaleCronCommand,
     CalendarOngoingStaleJob,
   ],
-  exports: [CalendarEventsImportService, CalendarFetchEventsService],
+  exports: [
+    CalendarEventsImportService,
+    CalendarFetchEventsService,
+    CalendarEventListFetchCronCommand,
+    CalendarEventsImportCronCommand,
+    CalendarOngoingStaleCronCommand,
+  ],
 })
 export class CalendarEventImportManagerModule {}