Implantation range and width is hard coded for W monoblock

https://github.com/kaelyndunnell/hisp/blob/ec9cb5d0acdef67a7523f83437df3050a9d1dd3f/src/hisp/festim_models/mb_model.py#L11-L13

We hard code these parameters for the W monoblock. Should they be dependent on incident energy and angle of incidence?

Also we should implement a reflection coefficient