Use ome-types (or alternatives) to represent metadata

[imagejan]

• to replace visiview.ome_companion_utils
• to replace metadata handling in other formats, i.e. hcs.cellvoyager and hcs.imagexpress

For example, this could be a mapping for the cellvoyager format:

channel_metadata.channel_name => Image.Pixels.Channel.id
channel_metadata.display_color => Image.Pixels.Channel.color
channel_metadata.spatial_calibration_x => Image.Pixels.physical_size_x with Image.Pixels.physical_size_x_unit
channel_metadata.spatial_calibration_y => Image.Pixels.physical_size_y with Image.Pixels.physical_size_y_unit
channel_metadata.spatial_calibration_units => per dimension, see above
channel_metadata.z_spacing => Image.Pixels.physical_size_z
channel_metadata.wavelength => Image.Pixels.Channel.emission_wavelength
channel_metadata.exposure_time => ?
channel_metadata.exposure_time_unit => ?
channel_metadata.objective => Image.ObjectiveSettings.id