For intersection at https://www.openstreetmap.org/node/65299217
`are_parallel` in MergableRoadDetector::HaveSameDirection is false
for South Van Ness Avenue with 150 meters
- separates node-based graph creation and compression from edge-based graph creation
- moves usage of edge-based node data-container to pre-processing as well, unifying access to node-based data
- single struct instead of separate vectors for annotation data in engine (single place of modification)
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
