Add rate limiting for notifications

**Feature request**
It would be great to have compression for controllers.

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

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

First resolve the conflict between the title, which requests notification rate limiting, and the body, which requests controller compression. Then identify the relevant controller and configuration entry points, confirm whether `enable_compression` with a default of `false` is the intended scope, and define completion criteria before starting implementation.

Written by the indexing model from the issue text.