Initialize F1AP

modify some issues
add f1ap ue context procedure

add DU_handle_DL_NR_RRC_MESSAGE_TRANSFER

 Conflicts:
	common/utils/ocp_itti/intertask_interface.h
	openair2/COMMON/gtpv1_u_messages_types.h
	openair2/GNB_APP/gnb_config.c
	openair2/RRC/NR/MESSAGES/asn1_msg.c
	openair2/RRC/NR/nr_rrc_proto.h
	openair2/RRC/NR/rrc_gNB.c
	openair2/RRC/NR/rrc_gNB_NGAP.c
	openair2/RRC/NR_UE/rrc_UE.c
	openair3/NAS/NR_UE/nr_nas_msg_sim.h
	openair3/NGAP/ngap_gNB_nas_procedures.c

 Conflicts:
	common/utils/ocp_itti/intertask_interface.h
	openair2/RRC/NR/rrc_gNB.c
	openair2/RRC/NR/rrc_gNB_NGAP.c
	openair2/RRC/NR_UE/rrc_UE.c
	openair2/RRC/NR_UE/rrc_defs.h
	openair3/NGAP/ngap_gNB_nas_procedures.c

MR932 : Nr sa ngap rrc wk42 
- Initial implementation of NGAP and RRC extensions for SA
 
MR956 : Correct use of ssb_position bitmaps  

MR958 : 5G NR Downlink DMRS Type 2
- Implementation of 5G NR Downlink DMRS type 2 (generation on gNB side, channel estimation with linear interpolation in frequency domain on UE side), needed for MIMO
  
MR961 : 5G NR UE TTI cleanup  
- Remove current_thread_id array, nr_tti_rx, nr_tti_tx, subframe_rx and subframe_tx

MR965 : fix a segdev

Conflicts:
	openair1/PHY/NR_UE_TRANSPORT/dci_nr.c
	openair1/PHY/NR_UE_TRANSPORT/nr_transport_proto_ue.h
	openair1/SCHED_NR_UE/phy_procedures_nr_ue.c

MR939 : Nr rlc am bugfix w44 
- bugfix

MR948 : nr: rlc: hotfix - forgot to store frame and subfram  
- minor bugfix

MR942 : Feature/make s1 mme port configurable 
- This patch adds an optional "port" option to set another sctp port than 36412 

MR959 : minor: remove a CPPCHECK error for NR RLC
- remove a CPPCHECK error (not a real error) for NR RLC

Merge remote-tracking branch 'origin/hotfix-minor-remove-nr-rlc-cppcheck-error' into integration_2020_wk47

Merge remote-tracking branch 'origin/feature/make-s1-mme-port-configurable' into integration_2020_wk47

Add rrc_gNB_send_NGAP_PDUSESSION_SETUP_RESP
Fix some problems about pdu session setup

MR890 : moving the OFDM phase rotation from RU to DU  
Moves the recently introduced phase rotations from RU to DU. 
This is important for setups that do not use the monolithic mode (like Benetel RRU).

MR944 : fix pdsch low prb 
Fix for DLSCH decoding for low TBS and for ULSCH. 
In the UE, DLSCH decoding stats are printed periodically for every 64 frames. 
DLSCH decoding is skipped if UE receives retransmission for successfully decoded CW.
 
MR946 : S1ap bugfix rab setup  
Fix a bug in S1AP

MR951 : CI NSA FR1 logging and reporting update  
Enhancement of gNB html + log report showing (RAPROC PUSCH check, dlsch and ulsch statistics)

M954 : Mac fixes wk45 2
Hotfix: preserves "low" delay (20-30ms) and correct HARQ retransmissions by disabling timing advance (TA)
Reduces log level, compiler warning, correct TA condition