Add support for Scheduled Lambdas

[johipsum]

In order to consume RSS feeds or similar it should be possible to execute a TriggerService function in a given interval. E.g. all 10 minutes. To do this we need to create a CloudWatch-Event that calls the TriggerService function in a configured time interval with a configured payload.

• [x] add CloudWatch-Event rule creator for Scheduled-Trigger-Services
• [x] enhance service-registry to mark scheduled and manual triggers
• [x] remove events and lambda event permissions when deleting a flowRun
• [ ] add the pissibility to activate and deactivate events (when deactivating/activating flows)

[johipsum]

Activating and deactivating of flows and its scheduled triggers is part of #76 Activate / Deactivate Flows