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