refactor merging of segregated roads

adjust to generalFindMaximum function
moved parallel detection to ratio/absolute based regression testing
considerably improved detection quality using normalised regression lines
only follow initial direction/narrow turns for parallel detection

src/extractor/guidance/turn_analysis.cpp

@@ -80,13 +80,13 @@ Intersection TurnAnalysis::operator()(const NodeID node_prior_to_intersection,
     TurnAnalysis::ShapeResult shape_result =
         ComputeIntersectionShapes(node_based_graph.GetTarget(entering_via_edge));
 
-    // assign valid flags to normalised_shape
+    // assign valid flags to normalized_shape
     const auto intersection_view = intersection_generator.TransformIntersectionShapeIntoView(
         node_prior_to_intersection,
         entering_via_edge,
-        shape_result.normalised_intersection_shape,
+        shape_result.annotated_normalized_shape.normalized_shape,
         shape_result.intersection_shape,
-        shape_result.merging_map);
+        shape_result.annotated_normalized_shape.performed_merges);
 
     // assign the turn types to the intersection
     return AssignTurnTypes(node_prior_to_intersection, entering_via_edge, intersection_view);
@@ -171,9 +171,8 @@ TurnAnalysis::ComputeIntersectionShapes(const NodeID node_at_center_of_intersect
     intersection_shape.intersection_shape =
         intersection_generator.ComputeIntersectionShape(node_at_center_of_intersection);
 
-    std::tie(intersection_shape.normalised_intersection_shape, intersection_shape.merging_map) =
-        intersection_normalizer(node_at_center_of_intersection,
-                                intersection_shape.intersection_shape);
+    intersection_shape.annotated_normalized_shape = intersection_normalizer(
+        node_at_center_of_intersection, intersection_shape.intersection_shape);
 
     return intersection_shape;
 }