[LMS-2231]: added file filtering, improved error handling

...stemsx/cisd/common/io/IHierarchicalContentNodeFilter.java

...isd/openbis/dss/generic/server/ftp/DSSFileSystemView.java

.../cisd/openbis/dss/generic/server/ftp/FtpServerConfig.java

...nbis/dss/generic/server/ftp/resolver/AbstractFtpFile.java

...generic/server/ftp/resolver/ExperimentFolderResolver.java

...ver/ftp/resolver/HierarchicalContentToFtpFileAdapter.java

...ss/generic/server/ftp/resolver/ProjectFolderResolver.java

...s/dss/generic/server/ftp/resolver/RootFolderResolver.java

.../dss/generic/server/ftp/resolver/SpaceFolderResolver.java

...er/ftp/resolver/TemplateBasedDataSetResourceResolver.java