DDF-537 Added source status for the current query to the result view.

- Added source query status to cometd endpoint query result response
- Added source status view to result list view
- Latest response is merged automatically if there are zero hits
DDF-537 Added displayed result count per source in query source status.
DDF-537 Improved naming of result count and hits in Query Status.
DDF-537 Muted display of total hits per source in source status.