Remove the remaining alternate top tasks

The last department are being migrated onto the new style services and
information links. This feature is no longer needed so remove it and all
the related styles to go along with it.
Merge pull request #1603 from alphagov/remove-alt-top-tasks

Remove the remaining alternate top tasks
Configure Whitehall search client

* Adds unified_search_client
Adds ServicesAndInformation resource

* Adds route, controller and views
Adds ServicesAndInformationCollection

* Adds ServicesAndInformationFinder to wrap Rummager call
* Adds ServicesAndInformationParser to extract required info from
  Rummager response
Filter organisations needs slug, not name

Look up responses by string rather than symbol
Updates gds-api-adapters to version 12.1.0

* Update necessary to use Rummager test helpers

* Changes tests to use Rummager test helpers in gds_api_adapters gem
Style services and information page
Actions PR comments

* Removes ServicesAndInformation#to_partial_path since it is not needed
* Corrects services and information route to comply with standard naming
* Moves 'full list of topics' link inside org Services and guidance
  conditional
* Corrects test to ensure it is using an org with featured services and
  guidance
Adds publication path for services and info
Removes link to full list of topics

* Removing the link will allow us to deploy the services and information
  page without there being an way in the UI to access it.

* Changes features to reflect removing the link

* Clarifies feature scenario

* Changes ServicesAndInformationParser:
  make more use of methods available on GdsApi::Response
  assign subsector_link in #parsed_content to :link instead of :slug

* Changes ServicesAndInformationParserTest to check that all necessary
  keys are present in the parsed content instead of relying on checking
  explicit values returned by the rummager test helpers

* Changes link text on services and information collection group

* Changes route not to use "and"
Changes services and info finder query

* Adds "count: 0" to search query to optimize rummager search
Merge pull request #1601 from alphagov/build-search-and-information-pages

Build search and information pages