Make EnergyLossWriter not require nbins

EnergyLossWriter requires that you supply axis, dX, and bins. So if you want to span the whole shower axis, you need to first calculate the slant depth of the axis.

A solution already exists in LongitudinalWriter to do this math for you. It just needs to be ported over.

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information