SDLPP: Allow changing coliders' position

Requires `updateSizeAndPosition` to be run on the parent container

sdlpp/sdlpp_collision.cpp

@@ -30,6 +30,14 @@ void CollisionPolygon::updateCollision( int x, int y, int w, int h,
     position = Vec2D< int >( original.getX() * w + x, original.getY() * h + y );
 }
 
+void CollisionPolygon::setPos(const Vec2D<double> &pos) {
+    original = pos;
+}
+
+void CollisionPolygon::setPos(double x, double y) {
+    setPos({x, y});
+}
+
 int CollisionPolygon::getX() const {
     return position.getX();
 }