refactor of post-processing

- moves collapse into a dedicated set of functions / files
 - make collapse scenarios distinct (slight performance cost)
 - reduce verbosity for short name segments (now actually working, was supposed to do so before)

include/util/debug.hpp

@@ -46,7 +46,7 @@ inline void print(const engine::guidance::RouteStep &step)
         std::cout << ")";
     }
     std::cout << "] name[" << step.name_id << "]: " << step.name << " Ref: " << step.ref
-              << " Pronunciation: " << step.pronunciation;
+              << " Pronunciation: " << step.pronunciation << "Destination: " << step.destinations;
 }
 
 inline void print(const std::vector<engine::guidance::RouteStep> &steps)