Removed Courier.isAssignedToRoad() since it was un-used
Removed the un-used roadToWorkerMap in GameMap. Roads and couriers now keep track of each other
Fixed a fault where the method to return the closest storage will return too early before it has gone through all storages
Removed GameMap::isHouseSiteAvailable since it's un-used.
Removed the roadNetwork member in GameMap since the same information is tracked in MapPoints. Updated getBuildingsWithinReac to use MapPoints instead and removed a supporting method that's no longer needed