SSDM-7430: Refactoring and performance improvements

.../dss/plugins/sync/harvester/HarvesterMaintenanceTask.java

...r/dss/plugins/sync/harvester/synchronizer/Connection.java

...s/plugins/sync/harvester/synchronizer/ConnectionType.java

...ugins/sync/harvester/synchronizer/EntitySynchronizer.java

.../plugins/sync/harvester/synchronizer/IncomingDataSet.java

...s/plugins/sync/harvester/synchronizer/IncomingEntity.java

...ugins/sync/harvester/synchronizer/IncomingExperiment.java

.../plugins/sync/harvester/synchronizer/IncomingProject.java

...s/plugins/sync/harvester/synchronizer/IncomingSample.java

...r/dss/plugins/sync/harvester/synchronizer/MasterData.java

...s/sync/harvester/synchronizer/MasterDataSynchronizer.java

...vester/synchronizer/MaterialWithLastModificationDate.java

...ugins/sync/harvester/synchronizer/ResourceListParser.java

...s/sync/harvester/synchronizer/ResourceListParserData.java

...s/sync/harvester/synchronizer/SynchronizationContext.java

...elizedExecutor/AttachmentSynchronizationTaskExecutor.java

...parallelizedExecutor/DataSetRegistrationTaskExecutor.java

...dss/plugins/sync/harvester/synchronizer/util/V3Utils.java

...penbis/dss/generic/server/EncapsulatedOpenBISService.java