message: Remove unused method `TileMap::edgeLength()`
diff: @@ -60,8 +60,6 @@ public:
  MapCoordinate mouseTilePosition() const { return {mMouseTilePosition, mOriginTilePosition.z}; }
  Tile& mouseTile();
  - int edgeLength() const { return mEdgeLength; }
  -
  void onMouseMove(NAS2D::Point<int> position);
  void onResize(NAS2D::Vector<int>);
  