Add configuration options for notifications

**Feature request**
It would be great to have monitoring for types.

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

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

No files, tests, or entry points are named. First locate the configuration parsing and notification or monitoring entry points, then determine which notification types are in scope and how enable_monitoring should affect them; done should include the documented default of false and tests covering the option.

Written by the indexing model from the issue text.