feat: Add a simple configurable notifications subscriber (#7331)

* feat: Add a simple configurable notifications subscriber that is configurable

* Proposal on awaiting all subscribers to run

* fix: Clean up wait subscribers util and notifications test

---------

Co-authored-by: adrien2p <adrien.deperetti@gmail.com>

packages/modules/providers/notification-local/integration-tests/__tests__/services.spec.ts

@@ -30,7 +30,7 @@ describe("Local notification provider", () => {
 
     expect(logSpy).toHaveBeenCalled()
     expect(logSpy).toHaveBeenCalledWith(
-      'Attempting to send a notification to: test@medusajs.com on the channel: email with template: some-template and data: {"username":"john-doe"}'
+      `Attempting to send a notification to: 'test@medusajs.com' on the channel: 'email' with template: 'some-template' and data: '{\"username\":\"john-doe\"}'`
     )
   })
 })