SSDM-13251: Refactoring new data store code

...src/main/java/ch/ethz/sis/afsclient/client/AfsClient.java

...c/main/java/ch/ethz/sis/afsclient/client/AfsClientV2.java

...ava/ch/ethz/sis/afsserver/http/impl/NettyHttpHandler.java

...a/ch/ethz/sis/afsserver/http/impl/NettyHttpHandlerV2.java

...a/ch/ethz/sis/afsserver/server/impl/ApiServerAdapter.java

...ch/ethz/sis/afsserver/server/impl/ApiServerAdapterV2.java

.../ch/ethz/sis/afsserver/core/AbstractPublicAPIWrapper.java

...h/ethz/sis/afsserver/core/AbstractPublicAPIWrapperV2.java

...a/ch/ethz/sis/afsserver/impl/APIServerAdapterWrapper.java

...ch/ethz/sis/afsserver/impl/APIServerAdapterWrapperV2.java

...est/java/ch/ethz/sis/afsserver/impl/APIServerWrapper.java

...t/java/ch/ethz/sis/afsserver/impl/APIServerWrapperV2.java

...java/ch/ethz/sis/afsserver/impl/ApiServerAdapterTest.java