increased develop version to 0.8.0
added interface for prefix ports
added draft implementation of FileStoreUIRPortObject
Added PortObjectSerializer and switched more occurrences of URIPortObject to IURIPortObject
made FileStoreURIPortObject relocatable
implemented filestore based prefix port
renamed package containing the ports and cleaned GKNModel a bit
fixed some more sonar issues related to the new code
increased required version of org.knime.base and org.knime.core.data.uritype

 * required as we now use the FileStorePortObject & Co.
Merge branch 'feature/filestore-port-objects' into develop
 * removed all references to FileStash
 * fixed some sonar issues
removed obsolete classes
fixed some more sonar issues in CTDConfigReader
some more sonar fixes
Merge branch 'feature/filestash-cleanup' into develop