OZG-7811 OZG-8099 Working registration of loaders

...n/java/de/ozgcloud/aggregation/AggregationDataLoader.java

...e/ozgcloud/aggregation/AggregationDataLoaderRegistry.java

...loud/aggregation/AggregationManagerGrpcConfiguration.java

...loud/aggregation/extern/AggregationDataRemoteService.java

...cloud/aggregation/extern/AggregationRemoteDataLoader.java

...zgcloud/aggregation/extern/GrpcAggregationDataMapper.java

...aggregation/warehouse/AggregationWarehouseDataLoader.java

...gcloud/aggregation/AggregationDataLoaderRegistryTest.java

...d/aggregation/extern/AggregationRemoteDataLoaderTest.java

...a/de/ozgcloud/aggregation/extern/SpringContextITCase.java

...egation/warehouse/AggregationWarehouseDataLoaderTest.java

...e/ozgcloud/aggregation/warehouse/SpringContextITCase.java