Signed-off-by: Raphael Defosseux <raphael.defosseux@eurecom.fr>

- nr_ulsim supports multiple DMRS configurations

Still problem with low MCS (same as PDSCH)

- start_rb was set to 30, and nb_rb was set to 50 with NB_RB_DL = 106.
- When the DC subcarrier is included in the RB allocation,
  this causes errors in FFT/IFFT operations arounf the DC subcarrier
- This leads to errors in unscrambling and decoding

Added the following folder:
- ../openair1/PHY/NR_ESTIMATION/

Added the following file to CMakelists.txt:
- ../openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c

Added the following functions:
- nr_pusch_dmrs_rx
- nr_gold_pusch
- nr_ulsch_channel_level
- nr_ulsch_channel_compensation
- nr_ulsch_scale_channel is commented out (I think only used for downlink)

Changes from Khalid Ahmed Mahmoud Mohamed:
- nr_pusch_channel_estimation is used
- nr_ulsch_scale_channel is used
- nr_ulsch_channel_level is used
- nr_ulsch_channel_compensation is used
- multiple logging options for channel and signal magnitude

- removed gNB RT from "ru_procedures.c" to "nr_ru_procedures"
- added a new thread "nr_feprx_thread"
- added some functionalities for fep for rx in "nr_ru_procedures.c"

- start_rb was set to 30, and nb_rb was set to 50 with NB_RB_DL = 106.
- When the DC subcarrier is included in the RB allocation,
  this causes errors in FFT/IFFT operations arounf the DC subcarrier
- This leads to errors in unscrambling and decoding

Added the following folder:
- ../openair1/PHY/NR_ESTIMATION/

Added the following file to CMakelists.txt:
- ../openair1/PHY/NR_ESTIMATION/nr_ul_channel_estimation.c

Added the following functions:
- nr_pusch_dmrs_rx
- nr_gold_pusch
- nr_ulsch_channel_level
- nr_ulsch_channel_compensation
- nr_ulsch_scale_channel is commented out (I think only used for downlink)

Changes from Khalid Ahmed Mahmoud Mohamed:
- nr_pusch_channel_estimation is used
- nr_ulsch_scale_channel is used
- nr_ulsch_channel_level is used
- nr_ulsch_channel_compensation is used
- multiple logging options for channel and signal magnitude

- removed gNB RT from "ru_procedures.c" to "nr_ru_procedures"
- added a new thread "nr_feprx_thread"
- added some functionalities for fep for rx in "nr_ru_procedures.c"

hotfix: replacing msg with printf in unitary simulators (msg(...) was replaced with LOG_D(PHY,...) but it was used before log was initialized)

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