Update performance tests.

[msaarine]

Basically only some small changes to get these 8 tests to work on Lenovo-X1 & Orin-NX as well. Needed to work with firewall settings. Other Devices than Lenovo-X1 or Orin-NX will use the original solution (iptables -F still left as was for the other targets)

Changes:

• Selection where to connect, if Lenovo or NX -> net-vm, other targets ghaf-host
• Opened port 5201 from iptables. Originally this was issue since using flushing (iptables -F ) in 'net-vm' got the net-vm into 'totally stucked -state.'
• Moved starting/stopping of 'iperf server' to Suite SetUp/Suite Teardown ( started/stopped only once -> more robust, and bit faster execution) compared to the original solution where iperf-server was started/stopped in every test separately.
• In local trials there was some random test failures-> added a keyword to check if the data collection was successfully passed or not. If not -> FAIL with clear statement.
• Added ' lenovo-x1' tags back for the tests