accomidate new search api response
update aggregate_by_url

  - Do encoding once in request call
  - provide different message for empty repsonse (vs error)
allow sopresto proxy to urlencode GET requests (specifically for search)
no need to check for url existance
check for response, before checking response->statuses is set
replicate "result" structure from aggregate_by_api method (which works
as expected)
Merge branch 'feature/search-api-change' into develop