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

- Initial gNB DLSCH and UE spec scheduling implentation
- MAC PDU generation (including header as per TS 38.321)
- MAC PDU processing at UE side with extracion of TA updates
- General code cleanup
- Introduced NR MAC COMMON folder, moved common files here

- TBS calculation was performed 2 times. Once in "phy_procedures_nrUE_TX" and
  another in "nr_ue_ulsch_procedures". The TBS calculation was wrong in "phy_procedures_nrUE_TX"
  and correct in "nr_ue_ulsch_procedures".

- The data generation was performed in "phy_procedures_nrUE_TX" with a wrongly
  calculated TBS because "ulsch_ue->nb_re_dmrs" wasn't set to a value, so the calculated
  TBS would be more than it should be. This doesn't create a problem in the test because
  the comparison between the TX and RX data is made using the correctly calculated TBS
  which is smaller.

- Solution was to perform data generation in "nr_ue_ulsch_procedures", and remove TBS calculation
  in "phy_procedures_nrUE_TX"

- removing "Nsymb_pusch" and "Nsc_pusch" from "NR_UE_ULSCH_t"
- using "number_of_symbols" from "NR_UL_UE_HARQ_t" instead
- removing "generate_ue_ulsch_params"

nr-ip-over-LTE: Resolved issue with duplicate IP packet at the receiver UE IP interface and packet losses are reduced. Remaining to identify why occasionally IP packets are received at the PDCP stack later than the time slot of their arrival at PHY/MAC. Introduced some debug logs, to be removed later.

nr-ip-over-LTE: Small fixes, now IP traffic is received at the IP interface of the UE but there are many packet losses and occasionally there are duplicate ping requests received, leading to UE crashing

- TBS calculation was performed 2 times. Once in "phy_procedures_nrUE_TX" and
  another in "nr_ue_ulsch_procedures". The TBS calculation was wrong in "phy_procedures_nrUE_TX"
  and correct in "nr_ue_ulsch_procedures".

- The data generation was performed in "phy_procedures_nrUE_TX" with a wrongly
  calculated TBS because "ulsch_ue->nb_re_dmrs" wasn't set to a value, so the calculated
  TBS would be more than it should be. This doesn't create a problem in the test because
  the comparison between the TX and RX data is made using the correctly calculated TBS
  which is smaller.

- Solution was to perform data generation in "nr_ue_ulsch_procedures", and remove TBS calculation
  in "phy_procedures_nrUE_TX"

- removing "Nsymb_pusch" and "Nsc_pusch" from "NR_UE_ULSCH_t"
- using "number_of_symbols" from "NR_UL_UE_HARQ_t" instead
- removing "generate_ue_ulsch_params"

fixing a bug in the allocation of the UE HARQ structures that was causing a segfault. Fixing some compiler warnings

- Setting the payload to random data instead of all zeros at the Tx side

- Handling "nb_symb_sch" equal to 0 in "phy_procedures_nrUE_RX" which prevents
  entering "nr_ue_pdsch_procedures"

- Handling symbol loop problem in "nr_ue_pdsch_procedures"

- Handling resource block loop problem in "nr_rx_pdsch"

however, I had to hardcode the parameters for the PUSCH in nr_ulsim as the fapi interface still has bugs.

Added Rx indication for DLSCH type and resolved issue with MIB decoding while sending DL IP traffic. Data packets still not parsed properly at the UE MAC layer.

 - dci_request and dl_indication for PBCH now also on stack
 - fixed type of nrUE_config (was using structure for gNB before)
 - added configuration of PBCH to phy_config_request and using this config now in phy_procedures_nr_ue
 - we need to add configuration of PDCCH and PDSCH also to phy_config_request (there are still some hardcoded parameters)
 - removed UL scheduling for now

- remove printf in nr_ulsch_coding.c
- renaming test_input to mac_pdu
- using memcpy for mac_pdu instead of pointing to data
- remove temp_nfapi struct from header file

- adding SCHED_NR_UE_LIB to ulsim compilation library
- fixing linking compilation problems
- using fapi_nr_dci_pdu_rel15_t struct to initialize PUSCH
- test_input random data is set in phy_procedures_nrUE_TX instead of ulsim

Final --phy_simulators warning removals for this branch, and former polar coding function corrections