Fileset examples fixes 11852 5_0

--rebased-from #1916

Updating examples/Training/python with examples of Bliltz Gateway API changes for OMERO 5 as part of openmicroscopy/ome-documentation#594

Fileset examples
conn.getAdministrators()
In running this code I found a Bug in Blitz Gateway which was fixed by subsequent commit.
To test, run the new code in the example files (substituting login and imageId as needed).