Item Image
Currently the full representation of item GET does not include the item image ('image_data') since that can be large. However if a request specifies the `fields` query string parameter and the 'image_data' field is specified, we will return the field and value.
This will return the id and image data for one or more items.
GET .../entity/item/?fields=id,image_data
This will return the id and image data for a specific item.
GET .../entity/item/{id}/?fields=id,image_data
The 'fields` parameter may still be combined with other filters per normal functionality:
GET
.../entity/item/?fields=id,image_data&barcode=ITEM123&...