A new Level 2 ROS test is defined, that is similar to the DDS loopback test
and can be used to measure the round trip time between a server and a client.
L2_Testbench_ROS_Lib6 is the server implementation, while L2_Testbench_ROS_Lib7
is the client implementation.
A custom (ROS) type is also defined (Type1).
Read the comments in L2_ROS_Loopback_test1 for implementation details.