You will have to investigate whether you can drive in the UK on a Dutch licence, google dvla who will be able to tell you. The reason that you will need the drivers licence is that their cadets are required to do all sorts of other jobs during their training in return for free training, one of those other jobs might be driving crews to the airport or driving spares to a grounded aircraft. Good luck with sorting out the licence and if you choose to apply for the course then good luck with that too.