Reduce BG_Types :: cMaxNoOfLinkedBGs to 4 to ease debugging

Signed-off-by: UweSteinkeFromSiemens <uwe.steinke@siemens.com>
CalculateTrainPosition: Implement BGs as a list sorted by the sequential order on track

Signed-off-by: UweSteinkeFromSiemens <uwe.steinke@siemens.com>