Enable automatic processing dlq's from configuration

[gklijs]

Enhancement Description

Build onto #2633 to allow process dlq.

Current Behaviour

No way to process by setting a property. The processor needs to be retrieved via configuration.

Wanted Behaviour

Have a few properties, like interval (int), process all (boolean), and enable processing (boolean). The implementation could use a ScheduledExecutorService. We could also set a property to use an executor service for all or have a separate executor service for all processing groups.

For more advanced use cases, like evicting the dlq after x time or x times, a manual configuration would still be needed. It's impossible to cover all cases by configuration.

Possible Workarounds

Manually setting it up.