Command class to advance a unit towards a given coordinate. UnitAdvanceToCoordinateCommand will get pathfinder for realm, find a path from unit's current coordinate to target coordinate and move unit towards it as long as it has enough movement points. If given unit is already at the target coordinate, this command will immediately return RESULT_OK.
Upon execution this command will return an error if:
- Pathfinder for realm is null.
- There is not any path from unit's current location to target tile.
- One of the MoveCommands returns error.
@author Deniz ARIKAN