New "sides" setting in base parameters for phantom nodes.

- Adding sides parameter into base parameters, it can take the values SIDE, OPPOSITE or DEFAULT.
 - Adding url parser for "sides" parameter, url values are "s" for SIDE, "o" for OPPOSITE and "d" for DEFAULT, example : "sides=s;s".
 - Checking parameters, if "sides" parameter is used, the number of parameter is the same as number of location.
 - Create a phantom to start at side driving or Opposite side driving.

Signed-off-by: FILLAU Jean-Maxime <jean-maxime.fillau@mapotempo.com>

include/engine/api/base_parameters.hpp

@@ -30,6 +30,7 @@ SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #include "engine/bearing.hpp"
 #include "engine/hint.hpp"
+#include "engine/side.hpp"
 #include "util/coordinate.hpp"
 
 #include <boost/optional.hpp>
@@ -55,6 +56,7 @@ namespace api
  *              optional per coordinate
  *  - bearings: limits the search for segments in the road network to given bearing(s) in degree
  *              towards true north in clockwise direction, optional per coordinate
+ *  - sides: force the phantom node to start towards the node with the road country side.
  *
  * \see OSRM, Coordinate, Hint, Bearing, RouteParame, RouteParameters, TableParameters,
  *      NearestParameters, TripParameters, MatchParameters and TileParameters
@@ -65,6 +67,7 @@ struct BaseParameters
     std::vector<boost::optional<Hint>> hints;
     std::vector<boost::optional<double>> radiuses;
     std::vector<boost::optional<Bearing>> bearings;
+    std::vector<boost::optional<Side>> sides;
 
     // Adds hints to response which can be included in subsequent requests, see `hints` above.
     bool generate_hints = true;
@@ -73,9 +76,10 @@ struct BaseParameters
                    const std::vector<boost::optional<Hint>> hints_ = {},
                    std::vector<boost::optional<double>> radiuses_ = {},
                    std::vector<boost::optional<Bearing>> bearings_ = {},
+                   std::vector<boost::optional<Side>> sides_ = {},
                    bool generate_hints_ = true)
         : coordinates(coordinates_), hints(hints_), radiuses(radiuses_), bearings(bearings_),
-          generate_hints(generate_hints_)
+          sides(sides_), generate_hints(generate_hints_)
     {
     }
 
@@ -85,6 +89,7 @@ struct BaseParameters
         return (hints.empty() || hints.size() == coordinates.size()) &&
                (bearings.empty() || bearings.size() == coordinates.size()) &&
                (radiuses.empty() || radiuses.size() == coordinates.size()) &&
+               (sides.empty() || sides.size() == coordinates.size()) &&
                std::all_of(bearings.begin(),
                            bearings.end(),
                            [](const boost::optional<Bearing> bearing_and_range) {