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

* added name, version, commit and operating system to user agent
* added plugins to generate required information
* added additional property file to merge the required information in existing application configuration
* added and adjusted tests

- 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(validation): move data validation and null checks from sender strategies to sender client to fail fast