Changes since v0.7: * New Forward tracking algorithm that replaces the previous one. Performance of the Forward tracking has improved substantially. * Configurations can now be defined by means of a JSON file. Details of how to add new configurable parameters are in the `contributing.md` file. * The default configuration is the "loose" configuration, which obtains much better physics efficiencies in the UT and Forward tracking (see [this presentation](https://indico.cern.ch/event/866032/contributions/3648860/attachments/1951637/3240124/campora_quagliani_forward_tracking.pdf)). * `std::filesystem` or `Boost.filesystem` are used, depending on the compiler version. * Retuned selections.