SSDM-7493: bug fixed in MasterDataDeliverer: wrong name of description attribute for validation plugins

SSDM-8083: PropertyTypePE extended with metaData map attribute. Reading and writing to database tested

SSDM-7493: extract file service path also from 'description' attributes of types, spaces, projects and vocabularies

SSDM-7639: NPE bug fixed in ch.systemsx.cisd.openbis.dss.generic.server.DataStoreService.cleanupSession(String)

SSDM-7639: improvements: Get rid of FileTransferSessionManager. Handle finishing download session on DSS clean up. Make Log4jBaseFileTransferLogger independent on log level. Test added to DownloadFileTest

SSDM-7328: Fix BioFormatsReaderLibraryTest because bioformats 6.0.0 changed behaviour for multi images TIFF if the images have different sizes. Instead of having one series with different depths the reader splits it into two series. For the old example TIFF file this was the case. In the new example all images have the same size.

check for missing mandatory properties before save, key-access for attributes