#1574 changes to search and dataset list page

- removed feature pages section
- removed blue bar from all pages except search / all tab
- putting counts in the tab titles <- this needed changes in the
controller in the way we search solr - until now, in the dataset tab we
were searching just for datasets so there was no way to get the count of
indicators
refactoring search controller #1591
Merge pull request #1635 from OCHA-DAP/search-dataset-changes

Pull request for: Search dataset changes