Addition of Real-Physics Customizable Calorimeter

This merge includes a new, fully customizable calorimeter application which is defined in GeantV using VecGeom libraries. This includes a macro file which provides an interface for a user to set their own arguments for the calorimeter in advance. This is a real-physics example application, and as such will be stored under the examplesRP folder.

The data structures and some of the possible input user files (userPhysicsList, CaloPrimaryGenerator, Hist, etc) were derived from the TestEm5 example, and as such many of the same data outputs are available (energy deposit in each type of absorber material, charged and neutral track length in each absorber material, number of charged/neutral steps, number of gammas/electrons/positrons generated, and so on). Additionally, the standard deviation of the track length and energy deposits are available, allowing for the calculation of the calorimeter's resolution.

A section of the application also allows for histogram generation, though the current example implementation is pedagogical (total energy deposition histogram for primaries which exit the calorimeter volume)