feat(coderd): add inbox notifications endpoints (#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

coderd/database/queries/notificationsinbox.sql

@@ -21,8 +21,8 @@ SELECT * FROM inbox_notifications WHERE
 -- param limit_opt: The limit of notifications to fetch. If the limit is not specified, it defaults to 25
 SELECT * FROM inbox_notifications WHERE
 	user_id = @user_id AND
-	template_id = ANY(@templates::UUID[]) AND
-	targets @> COALESCE(@targets, ARRAY[]::UUID[]) AND
+	(@templates::UUID[] IS NULL OR template_id = ANY(@templates::UUID[])) AND
+	(@targets::UUID[] IS NULL OR targets @> @targets::UUID[]) AND
 	(@read_status::inbox_notification_read_status = 'all' OR (@read_status::inbox_notification_read_status = 'unread' AND read_at IS NULL) OR (@read_status::inbox_notification_read_status = 'read' AND read_at IS NOT NULL)) AND
 	(@created_at_opt::TIMESTAMPTZ = '0001-01-01 00:00:00Z' OR created_at < @created_at_opt::TIMESTAMPTZ)
 	ORDER BY created_at DESC