Not paginated. A property carries a small, bounded number of media items, so the whole
set comes back in one call.

Media belongs to the building and units reference the items they display, so each item
lists the ids of the units pointing at it alongside displayOnBuilding. The same
file can therefore appear on the building and on several units at once.

order runs per media type, so an image and a floor plan can share a position.
Pass mediaType when you need a single, uninterrupted sequence.

url is an absolute, publicly fetchable address. Documents are a separate
resource and are not returned here.