Add OriginalMetadataRequest command (See #10349)

This adds a new API call (omero.cmd.OriginalMetadataRequest)
which returns globalMetadata and seriesMetadata for an image
id regardless of pre- or post-FS type.

Changes have been partially made to OmeroWeb for this to work,
but since a file annotation is no longer returned, further
changes will be needed. /cc @will-moore

Note: pre-FS data will be handled as part of #10703