Dipole Scaling Broken

[Laurie Nevay]

Using the scaling for dipole strengths doesn't work as intended. Issue to keep track.

[William Shields]

Fixed. The issue was only pertinent to the bdsimmatrix integrator set; the matrix used for dipole tracking was hard coded with the bending radius and relativistic beta as nominal parameters before scaling. This has since been updated so that they are recalculated for the scaled field. The particle's relative energy difference has been updated to be calculated w.r.t the nominal energy that a reference particle would have for that scaled field.