Filters an array of points returning those who falls inside a given Polygon
sourceArrayArray<google.maps.Marker> array of google.maps.MarkergeojsonPolygon(Polygon | Multipolygon) the polygon thay may contain the points
Returns {pointsInside: Array<google.maps.Marker>, pointsOutside: Array<google.maps.Marker>} an object with the points that fall inside and outside the polygon