Register detailed_guide route with panopticon

Include the route for a detailed guide when registering with panopticon.
This will enable us to remove the direct route registration for these,
which will in turn prevent detailed_guides from clobbering mainstream
content.
Remote detailed guide direct route registration

This removes the direct registration of routes for detailed guides as
this is now done via panopticon.

Note: this has left the sidekiq workers in place so that we can allow
the queues to empty before finally removing them.
Merge pull request #1428 from alphagov/fix_detailed_guide_route_registration

Register detailed guides' routes via Panopticon

https://www.pivotaltracker.com/story/show/69331956