- default enviroments for prod, test stage
- used defaults env can just be referenced via name in config.yaml
- custom envs can be added dynamically 

refactoring: merge DestinationService, Portalservice and KeyService to a sinblge services that deals with keys, use eventlogvirfier in eventLogService to reduce dependencies in sender and subscriber facade

- adds sending of accept- and reject-events
- adds fit-connect problems

refactor(config): remove metadata schema from config, file is loaded implicitly via factory from resources so the user does not have to provide a schema

refactor(config): print error with all available environments if the configured active environment is missing

- Rework der Applicationconfig zu yaml

Feature/15 Java SDK MVP Part I: contains implementations for sending & subscribing to submissions, adds commandline client