Improve nr_dlsim/nr_ulsim help message and CSV file logs

- Reorder help messages
- Add possibility to log results per SNR to CSV file with `-X` or `-Z`
- Reformat files

Co-authored-by: MoadMaroufi <maaroufi.moaad321@gmail.com>
Co-authored-by: francescomani <email@francescomani.it>
Co-authored-by: Robert Schmidt <robert.schmidt@openairinterface.org>