chore: fix sonar lint issues

.../fitconnect/api/domain/model/destination/Destination.java

.../de/fitko/fitconnect/api/domain/model/event/EventLog.java

...ct/api/domain/model/metadata/AdditionalReferenceInfo.java

...itconnect/api/domain/model/metadata/ContentStructure.java

.../fitko/fitconnect/api/domain/model/metadata/Metadata.java

...tconnect/api/domain/model/metadata/PublicServiceType.java

.../fitconnect/api/domain/model/metadata/data/Signature.java

...nect/api/domain/model/metadata/data/SubmissionSchema.java

...itko/fitconnect/api/domain/model/submission/Callback.java

...ko/fitconnect/api/domain/model/submission/Submission.java

...rc/main/java/de/fitko/fitconnect/client/SenderClient.java

...ain/java/de/fitko/fitconnect/client/SubscriberClient.java

...ava/de/fitko/fitconnect/client/cmd/CommandLineClient.java

...ko/fitconnect/client/factory/ApplicationConfigLoader.java

...ava/de/fitko/fitconnect/client/ClientIntegrationTest.java

...est/java/de/fitko/fitconnect/client/SenderClientTest.java

...java/de/fitko/fitconnect/client/SubscriberClientTest.java

...de/fitko/fitconnect/client/factory/ClientFactoryTest.java

...va/de/fitko/fitconnect/core/auth/DefaultOAuthService.java

...ain/java/de/fitko/fitconnect/core/crypto/HashService.java