- using LTE function mac_rrc_nr_data_req_ue in noS1 mode
- cleanup code, comments
- fixes RA procedure
- Processing UL MAC PDU according to TS 38.321 ch 6.1:
- introduced function for gNB side UL PDU processing
- fixed bug in nr_ue_process_mac_pdu

- Updated PRACH procedures and general code formatting
- gNB msg1 handling and RAR generation
- general bug fixing
- formatting
- missing headers
- RAR handling.

- merged nr-schedule_ue_spec into nr_schedule_uss_dlsch_phytest
- enabled nr_ue_send_sdu for S1 mode
- increased ta_timer to 100
- restored NR_UPLINK_SLOT to 2 (as it was in develop-nr)
- fixed logic for S1 and noS1 modes
- code cleanup and formatting

Integration PHY and MAC procedures for Timing Advance updates. Compilation and run is OK. TA updates need further fixes as not working as expected.

- "nr_process_timing_advance": TA to be applied is commented out, need to be uncommented
- with introduced delay of 50 in rx_rf, TA update should be 34 in MAC CE
  but this does not occur when ta is applied at UE side according to standard
- introduced ULSCH scheduler and NR RX SDU functions
- fixes to logic in UL fill RX indication
- added crc indication in UL RX
- temporary hardcoded UE_id to 0, rnti not considered in the logic