adding MAC part of 5G FAPI interface for PUSCH. Since the previous version was incomplete anyway I merged in the new SCF specs and used those (only for PUSCH). Todo: implement PHY part.

Downlink IP traffic flow using LTE RAN stack over NR-PHY. Downlink traffic reaching PHY of gNB now using the noS1 mode. Extensions required for the reception through the LTE RAN stack at the UE side.

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

--phy_simulators warning removals, except for nr_dlsim. Polar coding old implementation's approximation and a priori information options needs to be corrected or removed

- UE channel estimation no longer done in slot_fep. Also created dedicated memory for channel estimates of different channels
- using nr_extract_dci_info instead of nr_generate_ue_ul_dlsch_params_from_dci as in phy_procedures_nr_ue. The latter was only a (poor) wrapper and not doing what the name suggests. also with FAPI things have to be done differently now. This will come in a next commit.
- other minor changes to remove warning
prepreatory changes