SSDM-3907: prepare two example plugins for file system views

...s-with-data-sets-and-files-from-parents/plugin.properties

...tem-plugins/sample-types-with-data-sets/plugin.properties

...s/dss/generic/server/ftp/v3/V3DataSetContentResolver.java

.../dss/generic/server/ftp/v3/V3ExperimentLevelResolver.java

...sx/cisd/openbis/dss/generic/server/ftp/v3/V3Resolver.java

.../generic/server/ftp/v3/plugins/V3DataSetTypeResolver.java

...s/generic/server/ftp/v3/plugins/V3SampleTypeResolver.java