made L1 DLSCH encoding stateless. harq_pid/round information are not kept in PHY. Full channel encoding is performed for each transmission of a transport block.
Still to be done: test, then cleanup data structures and fix unitary simulations.

Conflicts:
        cmake_targets/CMakeLists.txt
        openair1/PHY/NR_UE_ESTIMATION/nr_ue_measurements.c
        openair1/PHY/NR_UE_TRANSPORT/nr_dlsch_decoding.c
        openair1/SCHED_NR/phy_procedures_nr_gNB.c
        openair2/RRC/NR/rrc_gNB.c
        openair2/RRC/NR_UE/rrc_UE.c
        openair2/LAYER2/nr_pdcp/nr_pdcp_oai_api.c
        openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_dlsch.c
        openair2/LAYER2/NR_MAC_UE/main_ue_nr.c
        openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c
        openair2/LAYER2/NR_MAC_gNB/main.c
        openair2/LAYER2/NR_MAC_UE/nr_ue_procedures.c
        openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c
        openair2/LAYER2/NR_MAC_UE/nr_ue_dci_configuration.c
        openair2/LAYER2/NR_MAC_gNB/gNB_scheduler.c
        openair2/LAYER2/nr_pdcp/nr_pdcp_entity_drb_am.c

The LDPC lifting size has to be stored for each harq_process as its only assigned in the first round.

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.

This commit contains work done by Eurecom and by Benetel.

Also fixed bugs in ulsim and dlsim harq tests

- ceiling computation num of segments (cod/dec)
- fixes demodulation
- initialisation CW for PDSCH RA
- memcpy dl_ch_estimates to pdsch_vars_ra (hotfix)
- correct N_RB for DCI 1_0 and RNTI_RA

temporary changes for nr_ulsim. To be removed when new branch with SCF NR FAPI for PUSCH is merged in.