issues found by valgrind

- a new section in the configuration file to select security algorithms,
  with new code to deal with it
- cleanup CG-ConfigInfo: specs seem to indicate that we must not
  add mcg_RB_Config; the gNB has to deal with that
- as a consequence, modify fill_default_rbconfig() that is called in
  every cases and needs security and bearer parameters

The new section in the configuration file looks like:

    security = {
      # preferred ciphering algorithms
      # the first one of the list that an UE supports in chosen
      # valid values: nea0, nea1, nea2, nea3
      ciphering_algorithms = ( "nea0", "nea2" );

      # preferred integrity algorithms
      # the first one of the list that an UE supports in chosen
      # valid values: nia0, nia1, nia2, nia3
      integrity_algorithms = ( "nia0" );
    };

Add rrc_gNB_send_NGAP_PDUSESSION_SETUP_RESP
Fix some problems about pdu session setup

Removed changes in fix_scc to avoid impact on the actual value of ssb_PositionsInBurst_Bitmap in the archived configuration files

MIB NR: pdcch_ConfigSIB1 selection and fill using the configuration file, and using a dynamic method.

This commit contains work done by Eurecom and by Benetel.

Modify kenb to kgnb
Modify some warnings