Add script to set the physical sizes post import

[sbesson]

From the submitters, The XY pixel units are 2 microns per pixel (0.5 pixels/micron), so a 250x250 pixel image represents a 500x500 micron field..

Since the raw data were PNG crops, this imaging metadata will need to be populated post import into the database.

[sbesson]

Briefly investigated yesterday, my initial hope was to get this achieve this tasks using the basic CLI command i.e.:

• omero hql to retrieve the list of images
• omero obj update Image:xxx physicalSizeX=yyy to set the property

Unfortunately, the last part fails due to the fact physical sizes are Length object and this is not supported by the obj update subcommand as discussed with @joshmoore.
This might require a Python script using the API although @dominikl was considering whether this could be turned into a mini CLI plugin.