Modelling Automation - implement App role changes

[tpurschke]

Allow the following workflow via API calls:

1. add new app servers to an app and to an app role
2. request Firewall changes for an app

This should be processed within 2-3 minutes and 1. must not collide with an existing import process.

Possible Implementation: Add technical Owner User to App which may modify Owner Data: Set a Owner.request_fw_changes flag. Middleware Automation Service should Monitor this field via Subscription and start Ticket creaction when true.