Move hierarchical_content stuff to openbis-common.

...sd/openbis/dss/generic/server/DatasetDownloadServlet.java

...enbis/dss/generic/server/api/v1/DssServiceRpcGeneric.java

.../openbis/dss/generic/server/ftp/resolver/FtpFileImpl.java

...s/dss/generic/shared/HierarchicalContentTraverseUtil.java

...content/PathInfoProviderBasedHierarchicalContentTest.java

...ch/systemsx/cisd/common/io/ByteArrayBasedContentNode.java

...stemsx/cisd/common/io/ConcatenatedContentInputStream.java

...java/ch/systemsx/cisd/common/io/FileBasedContentNode.java

.../HierarchicalContentNodeBasedHierarchicalContentNode.java

...mon/io/hierarchical_content/HierarchicalContentUtils.java

...mon/io/hierarchical_content/api/IHierarchicalContent.java

...io/hierarchical_content/api/IHierarchicalContentNode.java

...sx/cisd/common/io/ConcatenatedContentInputStreamTest.java

...ical_content/DefaultFileBasedHierarchicalContentTest.java