Make referee and api agree on what the 'home point' is

[SijmenHuizenga]

At the moment there are two 'home' points.

The primary home point is owned by the PhysXCarApi and is used almost everywhere. This home point is the ground truth translation between unreal engines coordinate system and the simulations global frame. This one is created in SimModeBase line 458.

The other owned by the referee (initial_position) who looks at the position of the vehicle when the game starts (in some blueprint). This one is used in the getRefereeState and all cones sent out through the referee state are relative to this point.

Having these two points is confusing and probably causes bugs (see #144). So let's fix this.