[refactory-2020] Refinements: documentation, typedefs, inline hints etc

corsika/detail/framework/random/RNGManager.inl

corsika/detail/modules/qgsjetII/qgsjet-II-04.inl

corsika/framework/core/Cascade.hpp

corsika/framework/random/ExponentialDistribution.hpp

corsika/framework/random/RNGManager.hpp

corsika/framework/random/UniformRealDistribution.hpp

corsika/modules/HadronicElasticModel.hpp

corsika/modules/pythia8/Interaction.hpp

corsika/modules/pythia8/Random.hpp

corsika/modules/qgsjetII/Interaction.hpp

corsika/modules/qgsjetII/Random.hpp

corsika/modules/sibyll/Interaction.hpp

corsika/modules/sibyll/NuclearInteraction.hpp

corsika/modules/sibyll/Random.hpp

corsika/modules/urqmd/Random.hpp

corsika/modules/urqmd/UrQMD.hpp