Add omero.cmd.fs.OriginalMetadataRequest

omero.cmd-based request which can load original metadata
(both global and series) for pre-FS and FS data.
Add test of OMR command. Currently failing.

The fixture.xml file had to be resurrected from the OmeroImporter
component in order to have makeImage() work. However, the test
is still failing likely because of issues with finding repos.