CI: AW2S pipeline - iperf test added, modifs in OC projects usage

• IPERF3 option created in cls_oaicitest.py
• retrieval of CN amf and traffic-server IP address from pods
• modification of gNB config file (do_SRS set, max UL MCS increased), removal of unused config file
• change of AmariUE config file to support 2x2
• modification of xml file for aw2s pipeline - iperf test added
• new xml file for cleanup (terminate AmariUE, clean test server images) created
• change of OC project for CN deployment
• change in OC project selection in PullClusterImage function
• BUILD-ONLY label selected for now,for testing purposes