Decorate all items with full thumbnail URL

[patrickarlt]

When developing applications I am constantly doing:

item.thumbnail = item.thumbnail
  ? `${portal}/content/items/${item.id}/info/${item.thumbnail}?${token}`
  : null;

since this is standard across everything so we should be able to do it any time we return an item from anywhere in REST JS and it would save all of us a lot of headache probably something more like this would handle token being optional for public items.

let thumbnailURL =  item.thumbnail
  ? `${portal}/content/items/${item.id}/info/${item.thumbnail}`
  : null;

if(thumbnailURL && item.access !== "public") {
   thumbnailURL += `?${token}`;
}

item.thumbnail = thumbnailURL

[jgravois]

you probably already saw it, but we're discussing the exact same thing for item resources in #322.

a generic utility method to assist with this would be awesome.

[tomwayson]

I think @jgravois meant #323

[jgravois]

yes. he did.

[tomwayson]

See also: https://gist.github.com/tomwayson/230aeeeefea46e574f732639464d5cf8#file-index-html-L118