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.

- Problem was related to UE_id and G

- Added nr_dft at UE side and nr_idft at gNB side
- NR_SC_FDMA can be found in "PHY/defs_nr_common.h"
- For 1 SNR loop, the code executes correctly
- For more loops, it gives a segmentation fault in the LDPC decoder
- The segmentation fault is caused when nr_idft is used
- The code works fine when the "NR_SC_FDMA" is disabled

- 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

- modifying generate_ue_ulsch_params to work with nfapi_nr_ul_config struct
- removing ulsim_params struct

implementing:
- generate_ue_ulsch_params (customized for ulsim only)
- nr_ue_ulsch_procedures
- nr_ue_pusch_common_procedures

- Added "nr_ulsch.c" file in NR_TRANSPORT
- Renamed "nr_ulsch.c" in NR_UE_TRANSPORT to "nr_ulsch_ue.c"
- Added "nr_ulsch_unscrambling" declaration to "nr_ulsch.h"
- Added "nr_ulsch_unscrambling" definition to "nr_ulsch.c"
- Added new test in "ulsim.c" to test encoding/decoding + scrambling/unscrambling

to ulsim.c and removed them from ulschsim.c

Also changed the linked libraries for the "ulsim.c" as it was causing linker problems