should add support for the images field from pipelines

[OriHoch]

after #76 is done, elasticsearch will provide images attribute which contains an array of image objects, something like this:

[
  {"url": "www.url.to.big.image", "thumbnail_url": "www.url.to.thumbnail.image"},
  ...
]

TO DO

• add this field to the index with proper mapping, once done - deploy the mojp-dbs-pipelines release
• return it for frontend (see Beit-Hatfutsot/dbs-front#449)

[OriHoch]

merged and deployed

now API responses for search and item will return the images array (if it exists in source data)

[OriHoch]

data was synced, it works - items have images now

[TheGrandVizier]

Yes they do.