Bug 1016241 - [Collections App] Populate collections with installed apps

The Bookmark's element's `dataset-identifier` will get `appId` instead of `appUrl`.
I suggest:

```
function PinnedWebResult(data) {
  data.renderer = GridIconRenderer.TYPE.CLIP;
  data.originalId = data.id;
  data.id = data.appUrl;
 
  return {
    identifier: data.appUrl,
    type: 'webResult',
    data: data
  };
...
```