Consider deprecating old components API

**Feature request**
It would be great to have notifications for routes.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_notifications` with default `false`.

The issue names no files or tests. Start by locating route handling and configuration parsing, then determine where route notifications would be wired and how the enable_notifications default is represented; done means the option controls notifications as described and the relevant behavior is covered by tests.

Written by the indexing model from the issue text.