Add missing test for db handler registrations

[soccermax]

tests did not detect typo in "db "

  if (config.processEventsAfterPublish) {
    cds.on("connect", (service) => {
      if (service.name === "db ") {
        dbHandler.registerEventQueueDbHandler(service);
      }
    });
  }

[soccermax]

• problem is runners are attached and picked up the work
• make sure events are processed by db handler
• add dedicated test that db handler is being registered