Magnet settings in compact file should be beam energy dependent

Not sure what the best way to do this is. For now may need to go for sed -i approach (which will need a convenience launcher to avoid mistakes).

• Clearly add ion beam energy into options file, and make FF magnets dependent on the ion energy (linear dependence will be fine, defaults are for 275GeV).
• Script that takes the compact file and replaces the baked-in beam energy with the correct one.