CI : Improvements to COTS-UE bench scripts

  -- Jenkins Pipeline script:
     -- Moved the node to a proper subnetwork
     -- Added ansiColor option
  -- XML testsuite file can now be an option to the main.py python script
     -- Added some examples testsuite templates
  -- main.py python file
     -- Added an option when opening an SSH session: taking care of clients with copied SSH keys
        in that case, verifing that we are on the correct host
     -- BuildeNB method is closer from Fujitsu's original one
        improvement on flexibility for code source path naming
        better clean-up of workspace
     -- LTEBOX EPC (init / termination / logCollection) methods improvements w/ a /tmp path
     -- Checking of processes (EPC / eNB) is parallelized
        also handles LTEBOX EPX vs OAI CN
     -- UE methods added: attach, detach, reboot, ping
        With complete parallelism for multiple UEs
        iperf added but not tested

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