filter images by Mapillary organization

[danbjoseph]

as part of assign_images filter images to only those from one or more defined organizations (this only applies to MAPILLARY and will not be relevant for LOCAL method). users should be able to define the one or more organization_id (int, ID of the organization this image belongs to. It can be absent." via Mapillary API docs) as an optional flag when running the script, or by adding it the the config files created in #48