- this commit was necessary because the location of the MAC UE
functions does not reflect the context in which they are used
- therefore all UL scheduling-related functions have been moved
to a new nr_ue_scheduler.c file
- and the irrelevant file rar_tools_nrUE.c has been deleted
(nr_ue_process_rar moved to nr_ue_procedures)
- the new locations are supposed to make the file and functions
organisations more structured and cleaner