feat(coderd): add inbox notifications endpoints (coder#16889)

This PR is part of the inbox notifications topic, and rely on previous
PRs merged - it adds :

- Endpoints to : 
  - WS : watch new inbox notifications
  - REST : list inbox notifications
  - REST : update the read status of a notification

Also, this PR acts as a follow-up PR from previous work and : 

- fix DB query issues
- fix DBMem logic to match DB

Author: defelmnq

cli/server.go

@@ -934,7 +934,7 @@ func (r *RootCmd) Server(newAPI func(context.Context, *coderd.Options) (*coderd.
 				// The notification manager is responsible for:
 				//   - creating notifiers and managing their lifecycles (notifiers are responsible for dequeueing/sending notifications)
 				//   - keeping the store updated with status updates
-				notificationsManager, err = notifications.NewManager(notificationsCfg, options.Database, helpers, metrics, logger.Named("notifications.manager"))
+				notificationsManager, err = notifications.NewManager(notificationsCfg, options.Database, options.Pubsub, helpers, metrics, logger.Named("notifications.manager"))
 				if err != nil {
 					return xerrors.Errorf("failed to instantiate notification manager: %w", err)
 				}