RadiationMapsMaker: Particle directions added; Memory footprint improved in finalize

Particle spectra can be generated with angular information (Theta and Delta Phi) added on top of the r/z/logE binning. This is needed to compare to TimePix data in ATLAS. The memory footprint in RadiatinMapsMakerTool::finalize() has been improved by creating each histogram directly before filling/writing and deleting directly after.