Dashboard is not able to cache factories

[sleshchenko]

Dashboard fetches factories each time instead of using cache with etag like he does with entities on other pages.

Reproduction Steps:

1. Create at least one factory in che.
2. Open factories page on dashboard and check requests list
   

Expected: First request returns 200 response code and next requests return 304.
Actual: All requests returns 200.

It works in this way because of wrong accepted rel that contains hash of GuiceUriBuilderImpl instance instead of link.

{
  "v": "4.0",
  "name": "test",
  ...
  "links": [
    ...
    {
      "href": "org.everrest.guice.GuiceUriBuilderImpl@7dcf6b95",
      "parameters": [],
      "rel": "accepted",
      "method": "GET",
      "produces": "text/plain"
    }
    ...
  ]
}