Try and make detailed guides look more like others

So that they have the same metadata stuff so we can add more metadata.
Add parent category document metadata

To replace functionality previously provided by the breadcrumb
Change "Detailed guidance" to "Guidance"

User and Editor feedback was that the term detailed guidance was confusing.
Fix to not barf when there is no primary category

Only detailed guides have primary categories. Pass these in explicitly and display if present.
Remove business link test
Remove test for breadcrumb inclusion
Remove unused hide extra logos
Remove unused title partials

Removed partials and styles which were only there for the removed
markup
Update placement of BL and EU logos

For the new heading structure the headings need to be in new places to
not look broken.
DetailedGudes are no longer unique
Merge pull request #1343 from alphagov/new-style-detailed-top

Use standard document top for detailed guides