Build search and information pages

Adds search and information page for organisations

Story: https://www.pivotaltracker.com/story/show/73388408

``content`` is not an hash, it is an ``GdsApi::Response`` object with its own ``to_hash`` method (please see https://github.com/alphagov/gds-api-adapters/blob/master/lib/gds_api/response.rb#L69).

I find that using the separate methods adds clarity as to what is being parsed, but I'm happy to revise that