Adapt PixelsService for accessing BF Readers for FS data
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.
Fix compile issues in other tests
Refactor TestPythonImporter for re-use
Call setId in PixelsService.getBfReader()
Revert seriesMetadata to a non-collection

Looking at the original_metadata.txt files under 4.4,
there is only a single series block in each file for
the given image, rather than series data for the entire
fileset.
Handle exception from getBfReader
Outline for handling pre-FS data (See #10703)
Python imports and initial repo test
Add method to omero.gateway with test
Fix impl after non-fake, hard-coded example
Merge pull request #1026 from joshmoore/10349-orig-metadata

Add OriginalMetadataRequest command (See #10349)