add softmodem-common.c and common error handler

executables/nr-softmodem-common.h

executables/nr-softmodem.c

executables/nr-softmodem.h

executables/nr-uesoftmodem.c

executables/nr-uesoftmodem.h

executables/softmodem-common.c

executables/softmodem-common.h

openair1/PHY/CODING/nrLDPC_encoder/ldpc_encoder2.c

openair1/PHY/phy_extern.h

openair1/PHY/phy_extern_nr_ue.h

openair1/PHY/phy_extern_ue.h

openair1/PHY/phy_vars.h

openair1/PHY/phy_vars_nr_ue.h

openair1/PHY/phy_vars_ue.h

openair2/ENB_APP/MACRLC_paramdef.h

openair2/ENB_APP/enb_config.c

openair2/ENB_APP/enb_paramdef.h

openair2/GNB_APP/gnb_config.c

openair2/GNB_APP/gnb_paramdef.h

openair2/LAYER2/NR_MAC_COMMON/nr_mac_extern.h