Green Belt - Implementation of speed and distance monitoring types

The main change is that the monitoring was put into a state machine and the speed and distance monitoring was adapted to handle errors and unusual cases (like indication location in rear of the train).

A number of tests were updated as the train position relative to the LRBG is now relevant for all tests (tests with LRBG in front of the train position needed to be updated). Other minor problems also required small modifications to the tests.