CRISP Spin Flipper

The CRISP Spin Flipper is generally reffered to as 'FLIPPRPS' in IOC and support files. It is a simple device for running polarised neutron experiments that can be set to either "up" or "down", presumably to polarise neutrons in one of those directions. The IOC is a stream device. The IOC was added based on this ticket originally: https://github.com/ISISComputingGroup/IBEX/issues/5338. However, it is unknown whether the IOC should be coordinating with the 'kepco' or not and this will be resolved with the following ticket: https://github.com/ISISComputingGroup/IBEX/issues/5415.