MR936: nr_fdd_if_fix
- Add support for 5G NR FDD bands and introduce configurable IF frequencies (esp. on nrUE) with configurable UL-DL-frequency offset. 
 
MR940: dongzhanyi-zte-develop2  
- Solved the problem that UE UL LDPC code can only process data within 8 code blocks (the UE UL LDPC code could only process data within 8 code blocks. If there were more than 8 code blocks, an error would occur)

MR943: NR_UE_MAC_scheduler
- Dynamic calculation of slot for PUSCH transmission based on slot offset k2. PUSCH slot is no longer hard-coded to 8.
- Support for multiple UL allocations in a frame by supporting a ul_config_request per UL slot.
- Support for multiple PDUs per slot
- Fixes for a few UE crashes/assertion failures due to invalid DCI received
- UE scheduler code clean-up

This reverts commit 199ce5d953ed90e052a69f520b30b7253b163250.

If UE receives retransmission for already decoded PDSCH, it skips decoding and sets ACK directly.
And adding PDSCH decoding stats and printing then every 64 frames for CI purpose

The BG was set to its default for rounds > 0. This is now fixed by adding it to harq structure.
Also a fix for wrong I_lbrm set in dlsch decoding.

Integration 2020 wk45 (2) comprising:

MR937:Nr dl sched fixes  
-restore old phytest scheduler behavior
-correct TA scheduling
-correct SSB
-shorten interface of `nr_fill_nfapi_dl_pdu()`
-Track RB allocation on symbol basis (bitmap)
-add a `remove_nr_ue_list()`, could be used instead of MR !934

MR910:5G SA NAS messages 
- 5G SA nass messages and a simple unitary test code
 
MR927:Nr rrc configuration fr2
- introduces some bug fixes for FR2 that might also have an impact on FR1.

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

 Conflicts:
	openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_bch.c

Conflicts:
	ci-scripts/conf_files/gnb.band78.tm1.106PRB.usrpn300.conf
	openair2/LAYER2/NR_MAC_UE/config_ue.c
	openair2/LAYER2/NR_MAC_gNB/config.c

The SSB nFAPI message is only sent every 8 frames, and automatically
repeated by the PHY layer in between. This commit sets the vrb_map
structure in those frames in between nFAPI so that the scheduler does
not schedule on such resources.

The phytest preprocessor schedules only one UE, as many RBs as possible
(largest continuous RB region), with a fixed MCS and time domain
allocation.