MSC: add test cases for concurrent MO/MT SS/USSD transactions

Both test cases make use of the existing functions:

  - TC_multi_lu_and_mo_ussd: f_tc_lu_and_mo_ussd_single_request(),
  - TC_multi_lu_and_mt_ussd: f_tc_lu_and_mt_ussd_notification(),

starting several (*) BSC_ConnHdlr components in parallel.

(*) The maximum amount is limited by 16 - this is as much
    as both GSUP and SCTP emulation components can handle.

Change-Id: I2fb1c5d285163d5245d92fa24c197a5027ecbe6f
Related: OS#2931
3 files changed